Configure the system-wide TCP connection timeout on OpenBSD

As there's no TCP connection timeout socket option that we can use, we
need to configure the TCP connection timeout system-wide in the CI, so
the netmgr unit tests doesn't cause assertion failure when there stuck
outgoing TCP connection waiting for 150 second timeout.
76 jobs for !4466 with ondrej/set-openbsd-system-connection-timeout in 12 seconds (queued for 7 seconds)
detached
Status Job ID Name Coverage
  Autoconf
canceled #1343828
amd64 linux
autoreconf

00:00:11

 
  Precheck
canceled #1343830
amd64 linux
clang-format

00:00:10

canceled #1343831
amd64 linux
coccinelle

00:00:09

canceled #1343832
amd64 linux
danger

00:00:09

canceled #1343829
amd64 linux
misc

00:00:10

canceled #1343833
amd64 linux
tarball-create

 
  Build
canceled #1343846
amd64 linux
clang:asan

canceled #1343850
amd64 linux
clang:buster:amd64

canceled #1343853
amd64 libvirt
clang:freebsd11:amd64

canceled #1343854
amd64 libvirt
clang:freebsd12:amd64

canceled #1343855
amd64 libvirt
clang:openbsd:amd64

canceled #1343848
amd64 linux
clang:tsan

canceled #1343834
amd64 linux
gcc:alpine3.12:amd64

canceled #1343845
amd64 linux
gcc:asan

canceled #1343838
amd64 linux
gcc:buster:amd64

canceled #1343835
amd64 linux
gcc:centos7:amd64

canceled #1343836
amd64 linux
gcc:centos8:amd64

canceled #1343844
amd64 linux
gcc:focal:amd64

canceled #1343849
amd64 linux
gcc:mutexatomics

canceled #1343840
amd64 linux
gcc:out-of-tree

canceled #1343839
amd64 linux
gcc:sid:amd64

canceled #1343841
i386 linux
gcc:sid:i386

canceled #1343851
amd64 linux
gcc:softhsm2.4

canceled #1343852
amd64 linux
gcc:softhsm2.6

canceled #1343837
amd64 linux
gcc:stretch:amd64

canceled #1343847
amd64 linux
gcc:tsan

canceled #1343842
amd64 linux
gcc:tumbleweed:amd64

canceled #1343843
amd64 linux
gcc:xenial:amd64

canceled #1343856
amd64 windows
msvc:windows:amd64

00:00:09

 
  Unit
canceled #1343868
amd64 linux
unit:clang:asan

canceled #1343872
amd64 linux
unit:clang:buster:amd64

canceled #1343875
amd64 libvirt
unit:clang:freebsd11:amd64

canceled #1343876
amd64 libvirt
unit:clang:freebsd12:amd64

canceled #1343877
amd64 libvirt
unit:clang:openbsd:amd64

canceled #1343870
amd64 linux
unit:clang:tsan

canceled #1343857
amd64 linux
unit:gcc:alpine3.12:amd64

canceled #1343867
amd64 linux
unit:gcc:asan

canceled #1343861
amd64 linux
unit:gcc:buster:amd64

canceled #1343858
amd64 linux
unit:gcc:centos7:amd64

canceled #1343859
amd64 linux
unit:gcc:centos8:amd64

canceled #1343866
amd64 linux
unit:gcc:focal:amd64

canceled #1343871
amd64 linux
unit:gcc:mutexatomics

canceled #1343862
amd64 linux
unit:gcc:sid:amd64

canceled #1343863
i386 linux
unit:gcc:sid:i386

canceled #1343873
amd64 linux
unit:gcc:softhsm2.4

canceled #1343874
amd64 linux
unit:gcc:softhsm2.6

canceled #1343860
amd64 linux
unit:gcc:stretch:amd64

canceled #1343869
amd64 linux
unit:gcc:tsan

canceled #1343864
amd64 linux
unit:gcc:tumbleweed:amd64

canceled #1343865
amd64 linux
unit:gcc:xenial:amd64

 
  System
canceled #1343889
amd64 linux
system:clang:asan

canceled #1343893
amd64 linux
system:clang:buster:amd64

canceled #1343896
amd64 libvirt
system:clang:freebsd11:amd64

canceled #1343897
amd64 libvirt
system:clang:freebsd12:amd64

canceled #1343891
amd64 linux allowed to fail
system:clang:tsan

canceled #1343878
amd64 linux
system:gcc:alpine3.12:amd64

canceled #1343888
amd64 linux
system:gcc:asan

canceled #1343882
amd64 linux
system:gcc:buster:amd64

canceled #1343879
amd64 linux
system:gcc:centos7:amd64

canceled #1343880
amd64 linux
system:gcc:centos8:amd64

canceled #1343887
amd64 linux
system:gcc:focal:amd64

canceled #1343892
amd64 linux
system:gcc:mutexatomics

canceled #1343883
amd64 linux
system:gcc:sid:amd64

canceled #1343884
i386 linux
system:gcc:sid:i386

canceled #1343894
amd64 linux
system:gcc:softhsm2.4

canceled #1343895
amd64 linux
system:gcc:softhsm2.6

canceled #1343881
amd64 linux
system:gcc:stretch:amd64

canceled #1343890
amd64 linux allowed to fail
system:gcc:tsan

canceled #1343885
amd64 linux
system:gcc:tumbleweed:amd64

canceled #1343886
amd64 linux
system:gcc:xenial:amd64

 
  Docs
canceled #1343898
amd64 linux
docs

 
  Postcheck
canceled #1343902
amd64 linux
cppcheck

canceled #1343899
amd64 linux
flake8

canceled #1343903
amd64 linux
gcov

canceled #1343900
amd64 linux
pylint

canceled #1343901
amd64 linux
scan-build