exchange: propagate arguments to the _getbundleextrapart function stable

exchange: propagate arguments to the _getbundleextrapart function

The arguments was wrongly propagated (again).

This a backport of 0055b5b3eb9c

--- a/mercurial/exchange.py	Wed May 07 17:20:38 2014 -0700
+++ b/mercurial/exchange.py	Wed May 07 19:28:17 2014 -0700
@@ -699,8 +699,8 @@
     bundler = bundle2.bundle20(repo.ui, b2caps)
     part = bundle2.bundlepart('b2x:changegroup', data=cg.getchunks())
     bundler.addpart(part)
-    _getbundleextrapart(bundler, repo, source, heads=None, common=None,
-                        bundlecaps=None, **kwargs)
+    _getbundleextrapart(bundler, repo, source, heads=heads, common=common,
+                        bundlecaps=bundlecaps, **kwargs)
     return util.chunkbuffer(bundler.getchunks())
 
 def _getbundleextrapart(bundler, repo, source, heads=None, common=None,