py3: use pycompat.bytestr() on extra values because it can be int...
py3: use pycompat.bytestr() on extra values because it can be int
One such example is {'close': 1} which marks a branch as closed.
This makes test-convert-mtn.t pass on Python 3.
Differential Revision:
https://phab.mercurial-scm.org/D5864
