mq: open status file et al in bytes mode

Differential Revision: https://phab.mercurial-scm.org/D1902

hgext/mq.py

@@ -695,7 +695,7 b' class queue(object):'
 
     def savedirty(self):
         def writelist(items, path):
-            fp = self.opener(path, 'w')
+            fp = self.opener(path, 'wb')
             for i in items:
                 fp.write("%s\n" % i)
             fp.close()