keepalive: remove pycompat.iteritems()

Differential Revision: https://phab.mercurial-scm.org/D12329

mercurial/keepalive.py

@@ -193,7 +193,7 b' class KeepAliveHandler(object):'
 
     def close_all(self):
         """close all open connections"""
-        for host, conns in pycompat.iteritems(self._cm.get_all()):
+        for host, conns in self._cm.get_all().items():
             for h in conns:
                 self._cm.remove(h)
                 h.close()