Merge branch 'test/mariadb-connector-c' into '2.12'

Use mariadb-connector-c for RHEL 8+

See merge request !25

https://github.com/Icinga/icinga-packaging/issues/205
14 jobs for 2.12 in 27 minutes (queued for 5 seconds)
Status Job ID Name Coverage
  Build
passed build/centos/7 #114099
docker

00:08:54

passed build/centos/8 #114098
docker

00:06:50

passed build/fedora/33 #114101
docker

00:17:10

passed build/fedora/34 #114100
docker

00:23:28

passed build/opensuse/15.2 #114104
docker

00:09:31

passed build/sles/12.5 #114103
docker

00:15:07

passed build/sles/15.2 #114102
docker

00:10:26

 
  Test
passed test/centos/7 #114106
docker

00:01:45

passed test/centos/8 #114105
docker

00:01:33

passed test/fedora/33 #114108
docker

00:01:55

passed test/fedora/34 #114107
docker

00:01:32

passed test/opensuse/15.2 #114111
docker

00:02:49

passed test/sles/12.5 #114110
docker

00:02:52

passed test/sles/15.2 #114109
docker

00:03:26