Added missing gettext import to changegroup.py.
--- a/mercurial/changegroup.py
+++ b/mercurial/changegroup.py
@@ -7,6 +7,7 @@ This software may be used and distribute
of the GNU General Public License, incorporated herein by reference.
"""
import struct
+from i18n import gettext as _
from demandload import *
demandload(globals(), "util")