warn if --repository provided for norepo commands

mercurial/dispatch.py

@@ -354,6 +354,8 b' def _dispatch(ui, args):'
                                       " here (.hg not found)"))
                 raise
         args.insert(0, repo)
+    elif rpath:
+        ui.warn("warning: --repository ignored\n")
 
     d = lambda: util.checksignature(func)(ui, *args, **cmdoptions)