[PATCH 1 of 2] bundle2: drop duplicated definition of 'b2x:exchange'

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1415268343 0
#      Thu Nov 06 10:05:43 2014 +0000
# Node ID d5d10a9e09e43ec3f9efe21d33321c698d81bb3d
# Parent  2d54aa5397cdb1c697673ba10b7618d5ac25c69e
bundle2: drop duplicated definition of 'b2x:exchange'

This bundle2 capability is going to be dynamically computed in 'getrepocaps'. We
do not need to include it in the static value.

diff --git a/mercurial/bundle2.py b/mercurial/bundle2.py
--- a/mercurial/bundle2.py
+++ b/mercurial/bundle2.py
@@ -869,11 +869,10 @@ class unbundlepart(unpackermixin):
         return data
 
 capabilities = {'HG2Y': (),
                 'b2x:listkeys': (),
                 'b2x:pushkey': (),
-                'b2x:changegroup': (),
                 'digests': tuple(sorted(util.DIGESTS.keys())),
                 'b2x:remote-changegroup': ('http', 'https'),
                }
 
 def getrepocaps(repo):