largefiles: make scheme regex a bytes regex

# skip-blame just a b prefix

Differential Revision: https://phab.mercurial-scm.org/D2338

hgext/largefiles/storefactory.py

@@ -80,7 +80,7 b' def openstore(repo=None, remote=None, pu'
     'ssh': [wirestore.wirestore],
     }
 
-_scheme_re = re.compile(r'^([a-zA-Z0-9+-.]+)://')
+_scheme_re = re.compile(br'^([a-zA-Z0-9+-.]+)://')
 
 def getlfile(ui, hash):
     return util.chunkbuffer(openstore(ui=ui)._get(hash))