hgweb: use native strings consistently for querystring parsing

Differential Revision: https://phab.mercurial-scm.org/D1078

mercurial/hgweb/hgweb_mod.py

@@ -187,7 +187,7 b' class requestcontext(object):'
         if style == styles[0]:
             vars['style'] = style
 
-        start = '&' if req.url[-1] == '?' else '?'
+        start = r'&' if req.url[-1] == r'?' else r'?'
         sessionvars = webutil.sessionvars(vars, start)
 
         if not self.reponame:

mercurial/hgweb/hgwebdir_mod.py

@@ -508,7 +508,7 b' class hgwebdir(object):'
         if style == styles[0]:
             vars['style'] = style
 
-        start = '&' if url[-1] == '?' else '?'
+        start = r'&' if url[-1] == r'?' else r'?'
         sessionvars = webutil.sessionvars(vars, start)
         logourl = config('web', 'logourl')
         logoimg = config('web', 'logoimg')