gitlab-ci: Fix it after upgrade
gitlab-ci: Fix it after upgrade

It seems that the regular expression parser changed in GitLab 12.1 and
now does now support forward slashes in the RE, even when escaped.

sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc