py3: use pycompat.bytestr() where repr in involved

Differential Revision: https://phab.mercurial-scm.org/D3244

hgext/mq.py

@@ -1164,7 +1164,7 b' class queue(object):'
         for c in ('#', ':', '\r', '\n'):
             if c in name:
                 raise error.Abort(_('%r cannot be used in the name of a patch')
-                                 % c)
+                                 % pycompat.bytestr(c))
 
     def checkpatchname(self, name, force=False):
         self.checkreservedname(name)