Merge PR #22870 into master

* refs/pull/22870/head:
	mgr: replace iteritems with six.iteritems (mgr_module.py)
	mgr: replace iteritems with six.iteritems (crash)
	mgr: replace iteritems with six.iteritems (telegraf)
	mgr: replace iteritems with six.iteritems (status)
	mgr: replace iteritems with six.iteritems (restful)
	mgr: replace iteritems with six.iteritems (influx)
	mgr: replace iteritems with six.iteritems (balancer)

Reviewed-by: John Spray <john.spray@redhat.com>
Reviewed-by: Wido den Hollander <wido@42on.com>
Reviewed-by: Kefu Chai <kchai@redhat.com>