py3: pass a bytes value for "msg" to nouideprecwarn()...
py3: pass a bytes value for "msg" to nouideprecwarn()
That function formats "msg" with the "version" value. On Python 3, this
leads to "TypeError: can only concatenate str (not "bytes") to str".
Also eliminate spurious strings concatenation in single-line
declarations.
Differential Revision:
https://phab.mercurial-scm.org/D7373
