request: use trivial iterator over dictionary keys

Differential Revision: https://phab.mercurial-scm.org/D968

mercurial/hgweb/request.py

@@ -39,7 +39,7 b' shortcuts = {'
 
 def normalize(form):
     # first expand the shortcuts
-    for k in shortcuts.iterkeys():
+    for k in shortcuts:
         if k in form:
             for name, value in shortcuts[k]:
                 if value is None: