remote-hg: properly mark branches up-to-date

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-remote-hg

@@ -742,6 +742,10 @@ def do_export(parser):
 
     for ref, node in parsed_refs.iteritems():
         if ref.startswith('refs/heads/branches'):
+            branch = ref[len('refs/heads/branches/'):]
+            if branch in branches and node in branches[branch]:
+                # up to date
+                continue
             print "ok %s" % ref
         elif ref.startswith('refs/heads/'):
             bmark = ref[len('refs/heads/'):]