exchange: directly 'getchangegroup'

It is identical to 'getlocalchangegroup' with a shorter name.

mercurial/exchange.py

@@ -950,7 +950,7 b' def _pushchangeset(pushop):'
                                    'push',
                                    fastpath=True)
     else:
-        cg = changegroup.getlocalchangegroup(pushop.repo, 'push', outgoing)
+        cg = changegroup.getchangegroup(pushop.repo, 'push', outgoing)
 
     # apply changegroup to remote
     if unbundle: