ITS#8589 syncrepl: defer on REFRESH_REQUIRED

Schedule a new retry instead of immediate looping back. This
will also prevent locking up cn=config replication.
3 jobs for master in 46 minutes and 14 seconds (queued for 34 minutes and 40 seconds)
Status Name Job ID Coverage
  Build
passed build-gnutls-mit-standalone-lloadd #5362

00:43:43

passed build-no-threads-no-slapd #5360

00:02:30

passed build-openssl-heimdal-lloadd #5361

00:45:16