gitlab module: restart services on failure

Sidqkiq regularly dies due to memory leaks.

nixos/modules/services/misc/gitlab.nix

@@ -380,6 +380,7 @@ in {
         User = cfg.user;
         Group = cfg.group;
         TimeoutSec = "300";
+        Restart = "on-failure";
         WorkingDirectory = "${cfg.packages.gitlab}/share/gitlab";
         ExecStart="${cfg.packages.gitlab.env}/bin/bundle exec \"sidekiq -q post_receive -q mailers -q system_hook -q project_web_hook -q gitlab_shell -q common -q default -e production -P ${cfg.statePath}/tmp/sidekiq.pid\"";
       };
@@ -404,6 +405,7 @@ in {
         User = cfg.user;
         Group = cfg.group;
         TimeoutSec = "300";
+        Restart = "on-failure";
         ExecStart =
           "${cfg.packages.gitlab-workhorse}/bin/gitlab-workhorse "
           + "-listenUmask 0 "