py3: add some b'' prefixes in hgext/convert/monotone.py
# skip-blame because just b'' prefixes
Differential Revision: https://phab.mercurial-scm.org/D5863
py3: use '%d' for integers instead of '%s'
I think this is the last of these occurences because I have got the test passing
on python3 in a later patch.
Differential Revision: https://phab.mercurial-scm.org/D5862