Fix review request for already known commitID

If someone pushed a commit to a tag only instead to a branch
it was not recognized as "already known commit" it the hooks
tried to create another review request for the same commit.

So let's check tag for already known commits, too.

contrib/mercurial_git_push.py

@@ -1433,12 +1433,17 @@ class GitRevision(BaseRevision):
     """Class to represent information of changeset."""
 
     @staticmethod
-    def fetch_known_branches(rev):
-        output = execute(['git', 'branch', '--contains', rev])
-        branches = []
-        for branch in output.splitlines():
-            branches.append(branch.replace('*', '').strip())
-        return branches
+    def fetch_known_refs(rev):
+        output = execute(['git', 'for-each-ref', '--contains', rev])
+        refs = []
+        for line in output.splitlines():
+            values = line.split()
+            if values[1] in ('commit', 'tag') and (
+                'refs/heads/' in values[2] or
+                'refs/tags/' in values[2]
+            ):
+                refs.append(values[2])
+        return refs
 
     @staticmethod
     def fetch_raw(node, base, skipKnown=True):
@@ -1454,7 +1459,7 @@ def fetch_raw(node, base, skipKnown=True):
 
         if skipKnown:
             def isKnown(rev):
-                return len(GitRevision.fetch_known_branches(rev)) > 0
+                return len(GitRevision.fetch_known_refs(rev)) > 0
             changes[:] = [x for x in changes if not isKnown(x)]
         return changes
 
@@ -1545,7 +1550,7 @@ def hasDangling(self):
         if self._has_dangling is None:
             self._has_dangling = (
                 self.isMerge() and
-                len(GitRevision.fetch_known_branches(self.parent(1))) == 0
+                len(GitRevision.fetch_known_refs(self.parent(1))) == 0
             )
         return self._has_dangling