Correct Gerrit Change-Id commentlink

* modules/openstack_project/manifests/gerrit.pp: Use a match group
around the pattern for a Change-Id since Gerrit doesn't interpret $0
as a backreference to the full pattern.

Change-Id: I711e8a1d7bc0b2f3eff07425badf2cb2c1740bf6

modules/openstack_project/manifests/gerrit.pp

@@ -160,8 +160,8 @@ class openstack_project::gerrit (
       },
       {
         name  => 'changeid',
-        match => 'I[0-9a-f]{8,40}',
-        link  => '#q,$0,n,z',
+        match => '(I[0-9a-f]{8,40})',
+        link  => '#q,$1,n,z',
       },
       {
         name  => 'gitsha',