Prevent Git to expand $systest

CentOS 8 "git status" unexpectedly expands search directory "tsig" to
also search in the "tsiggss" directory, thus incorrectly identifying
files as "not removed" in the "tsig" directory:

$ git status -su --ignored tsig
$ touch tsiggss/ns1/{named.run,named.memstats}
$ git status -su --ignored tsig
!! tsiggss/ns1/named.memstats
!! tsiggss/ns1/named.run

(cherry picked from commit f310b752)
87 jobs for !4705 with mnowak/system-test-check-for-file-not-removed-v9_11 in 26 minutes and 3 seconds (queued for 8 seconds)
detached
Status Job ID Name Coverage
  Precheck
passed #1504541
amd64 linux
autoreconf

00:00:25

passed #1504543
amd64 linux
clang-format

00:00:13

passed #1504544
amd64 linux
coccinelle

00:01:09

passed #1504545
amd64 linux
danger

00:00:20

passed #1504542
amd64 linux
misc

00:00:23

 
  Build
passed #1504560
amd64 linux
clang:asan

00:04:25

passed #1504566
amd64 linux
clang:buster:amd64

00:02:02

passed #1504568
amd64 libvirt
clang:freebsd11:amd64

00:02:01

passed #1504569
amd64 libvirt
clang:freebsd12:amd64

00:01:56

passed #1504570
amd64 libvirt
clang:openbsd:amd64

00:04:57

passed #1504562
amd64 linux
clang:tsan

00:02:23

passed #1504564
amd64 linux
clang:tsan:noatomics

00:02:29

passed #1504546
amd64 linux
gcc:alpine3.12:amd64

00:01:52

passed #1504559
amd64 linux
gcc:asan

00:04:17

passed #1504552
amd64 linux
gcc:buster:amd64

00:01:27

passed #1504548
amd64 linux
gcc:centos6:amd64

00:01:24

passed #1504547
i386 linux
gcc:centos6:i386

00:01:48

passed #1504549
amd64 linux
gcc:centos7:amd64

00:01:28

passed #1504550
amd64 linux
gcc:centos8:amd64

00:01:40

passed #1504556
amd64 linux
gcc:fedora33:amd64

00:01:37

passed #1504558
amd64 linux
gcc:focal:amd64

00:01:39

passed #1504565
amd64 linux
gcc:noatomics

00:02:26

passed #1504554
amd64 linux
gcc:out-of-tree

00:01:35

passed #1504567
amd64 linux
gcc:pkcs11

00:01:33

passed #1504553
amd64 linux
gcc:sid:amd64

00:02:14

passed #1504551
amd64 linux
gcc:stretch:amd64

00:02:04

passed #1504561
amd64 linux
gcc:tsan

00:02:04

passed #1504563
amd64 linux
gcc:tsan:noatomics

00:02:02

passed #1504555
amd64 linux
gcc:tumbleweed:amd64

00:01:39

passed #1504557
amd64 linux
gcc:xenial:amd64

00:01:54

passed #1504572
amd64 windows
msvc:windows:amd64

00:00:57

passed #1504571
amd64 linux
nolibtool:sid:amd64

00:02:11

 
  Unit
passed #1504586
amd64 linux
unit:clang:asan

00:01:17

passed #1504592
amd64 linux
unit:clang:buster:amd64

00:00:36

passed #1504594
amd64 libvirt
unit:clang:freebsd11:amd64

00:01:12

passed #1504595
amd64 libvirt
unit:clang:freebsd12:amd64

00:01:01

passed #1504588
amd64 linux
unit:clang:tsan

00:04:09

passed #1504590
amd64 linux
unit:clang:tsan:noatomics

00:04:18

passed #1504573
amd64 linux
unit:gcc:alpine3.12:amd64

00:00:35

passed #1504585
amd64 linux
unit:gcc:asan

00:01:19

passed #1504579
amd64 linux
unit:gcc:buster:amd64

00:01:05

passed #1504575
amd64 linux
unit:gcc:centos6:amd64

00:00:39

passed #1504574
i386 linux
unit:gcc:centos6:i386

00:00:37

passed #1504576
amd64 linux
unit:gcc:centos7:amd64

00:00:33

passed #1504577
amd64 linux
unit:gcc:centos8:amd64

00:00:34

passed #1504582
amd64 linux
unit:gcc:fedora33:amd64

00:00:36

passed #1504584
amd64 linux
unit:gcc:focal:amd64

00:00:36

passed #1504591
amd64 linux
unit:gcc:noatomics

00:00:33

passed #1504593
amd64 linux
unit:gcc:pkcs11

00:00:30

passed #1504580
amd64 linux
unit:gcc:sid:amd64

00:00:30

passed #1504578
amd64 linux
unit:gcc:stretch:amd64

00:00:33

passed #1504587
amd64 linux
unit:gcc:tsan

00:05:03

passed #1504589
amd64 linux
unit:gcc:tsan:noatomics

00:05:04

passed #1504581
amd64 linux
unit:gcc:tumbleweed:amd64

00:00:35

passed #1504583
amd64 linux
unit:gcc:xenial:amd64

00:00:36

passed #1504596
amd64 linux
unit:nolibtool:sid:amd64

00:00:53

 
  System
passed #1504610
amd64 linux
system:clang:asan

00:09:25

passed #1504616
amd64 linux
system:clang:buster:amd64

00:07:23

passed #1504618
amd64 libvirt
system:clang:freebsd11:amd64

00:08:19

passed #1504619
amd64 libvirt
system:clang:freebsd12:amd64

00:08:17

passed #1504612
amd64 linux
system:clang:tsan

00:11:48

passed #1504614
amd64 linux
system:clang:tsan:noatomics

00:11:24

passed #1504597
amd64 linux
system:gcc:alpine3.12:amd64

00:07:28

passed #1504609
amd64 linux
system:gcc:asan

00:09:55

passed #1504603
amd64 linux
system:gcc:buster:amd64

00:08:25

passed #1504599
amd64 linux
system:gcc:centos6:amd64

00:07:29

passed #1504598
i386 linux
system:gcc:centos6:i386

00:06:50

passed #1504600
amd64 linux
system:gcc:centos7:amd64

00:07:38

passed #1504601
amd64 linux
system:gcc:centos8:amd64

00:07:24

passed #1504606
amd64 linux
system:gcc:fedora33:amd64

00:07:28

passed #1504608
amd64 linux
system:gcc:focal:amd64

00:07:11

passed #1504615
amd64 linux
system:gcc:noatomics

00:07:06

passed #1504728
amd64 linux
system:gcc:pkcs11

00:08:35

passed #1504604
amd64 linux
system:gcc:sid:amd64

00:07:10

passed #1504602
amd64 linux
system:gcc:stretch:amd64

00:07:08

passed #1504611
amd64 linux
system:gcc:tsan

00:13:29

passed #1504613
amd64 linux
system:gcc:tsan:noatomics

00:13:24

passed #1504605
amd64 linux
system:gcc:tumbleweed:amd64

00:07:12

passed #1504607
amd64 linux
system:gcc:xenial:amd64

00:07:05

passed #1504620
amd64 linux
system:nolibtool:sid:amd64

00:07:19

failed #1504617
amd64 linux
system:gcc:pkcs11

00:08:12

 
  Docs
passed #1504621
amd64 linux
docs

00:00:31

 
  Postcheck
passed #1504625
amd64 linux
cppcheck

00:00:27

passed #1504622
amd64 linux
flake8

00:00:20

passed #1504626
amd64 linux
gcov

00:00:36

74.0%
passed #1504623
amd64 linux
pylint

00:00:25

passed #1504624
amd64 linux
scan-build

00:09:26