Prevent a race in the "inline" system test

A short time window exists between logging the addition of an NSEC3PARAM
record to a zone and committing it to the current version of the zone
database.  If a query arrives during such a time window, an unsigned
response will be returned.  One of the checks in the "inline" system
test requires NSEC3 records to be present in an answer - that check
would fail in the case described above.  Use rndc instead of log
watching for checking whether zone signing and NSEC3 chain modifications
are complete in order to prevent intermittent "inline" system test
failures.

(cherry picked from commit e36c869e)
14 jobs for 491-prevent-a-race-in-the-inline-system-test-v9_12 in 8 minutes and 31 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #44842
amd64 docker linux

00:00:13

 
  Build
passed build:centos:centos6:amd64 #44843
amd64 docker linux

00:02:45

passed build:centos:centos7:amd64 #44844
amd64 docker linux

00:02:45

passed build:debian:sid:amd64 #44845
amd64 docker linux

00:02:58

passed build:debian:sid:i386 #44846
i386 docker linux

00:01:21

 
  Test
passed install:debian:sid:amd64 #44855
amd64 docker linux

00:02:57

passed systemtest:centos:centos6:amd64 #44851
amd64 docker linux

00:05:00

passed systemtest:centos:centos7:amd64 #44852
amd64 docker linux

00:04:52

passed systemtest:debian:sid:amd64 #44853
amd64 docker linux

00:05:07

passed systemtest:debian:sid:i386 #44854
i386 docker linux

00:05:17

passed unittest:centos:centos6:amd64 #44847
amd64 docker linux

00:01:10

passed unittest:centos:centos7:amd64 #44848
amd64 docker linux

00:01:11

passed unittest:debian:sid:amd64 #44849
amd64 docker linux

00:00:44

passed unittest:debian:sid:i386 #44850
i386 docker linux

00:01:01