GitLab's Merge Requests are using ! not #

[EppO]

fixes #948

Thanks to the ground work from #983, we can now configure GitLab's Merge Request links in the Lock Message correctly, using ! instead of # which refers to issues, not MRs.

[codecov]

Codecov Report

Merging #1059 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1059   +/-   ##
=======================================
  Coverage   71.47%   71.47%           
=======================================
  Files          67       67           
  Lines        5556     5556           
=======================================
  Hits         3971     3971           
  Misses       1271     1271           
  Partials      314      314           

Impacted Files	Coverage Δ
server/events/vcs/gitlab_client.go	39.66% <100.00%> (ø)

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[lkysow]

Nice, thanks for the PR and thanks to @mcdafydd for laying that groundwork!

[EppO]

Can't take the credit for that one, @mcdafydd made it so easy for me :)
Thanks for the fast feedback @lkysow, really appreciated