hgweb: don't access self.repo during request processing

We want all repository accesses to go through requestcontext.repo
so the request is isolated from the application.

mercurial/hgweb/hgweb_mod.py

@@ -324,7 +324,7 b' class hgweb(object):'
                     raise ErrorResponse(HTTP_NOT_FOUND)
                 if cmd in perms:
                     self.check_perm(rctx, req, perms[cmd])
-                return protocol.call(self.repo, req, cmd)
+                return protocol.call(rctx.repo, req, cmd)
             except ErrorResponse as inst:
                 # A client that sends unbundle without 100-continue will
                 # break if we respond early.