remote-hg: do not interfer with hg's revs() method
Matt Mackall introduced a revs() method to the localrepo class on Wed
Nov 2 13:37:34 2011 in the commit 'localrepo: add revs helper method'.
It is used when constructing a commit in memory.
If we store the set of revs we want to handle under the same name, it
overrides that method, resulting in an unpleasant 'TypeError: 'set'
object is not callable' whenever we want to push (as we are constructing
commits in memory, then).
So let's work around that by renaming our field to 'revs2' and hope that
upstream Mercurial does not introduce a field of that name, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>