nixos/gitlab: Clean up the initializers on start

The initializers directory is populated with files from the gitlab
distribution on start, but old files will be left in the state folder
even if they're removed from the distribution, which can lead to
startup failures. Fix this by always purging the directory on start
before populating it.

nixos/modules/services/misc/gitlab.nix

@@ -780,6 +780,7 @@ in {
           preStart = ''
             cp -f ${cfg.packages.gitlab}/share/gitlab/VERSION ${cfg.statePath}/VERSION
             rm -rf ${cfg.statePath}/db/*
+            rm -rf ${cfg.statePath}/config/initializers/*
             cp -rf --no-preserve=mode ${cfg.packages.gitlab}/share/gitlab/config.dist/* ${cfg.statePath}/config
             cp -rf --no-preserve=mode ${cfg.packages.gitlab}/share/gitlab/db/* ${cfg.statePath}/db