ITS#8102 syncrepl: only use trylock on the cn=config DB

3 jobs for syncmutex in 37 minutes and 29 seconds (queued for 21 minutes and 18 seconds)
Status Job ID Name Coverage
  Build
passed #2185
build-gnutls-mit

00:29:45

passed #2183
build-no-threads-no-slapd

00:03:19

passed #2184
build-openssl-heimdal

00:28:29