Reset peer outboundproxy on sip.conf reload

If you set a peer's outboundproxy and then removed it from the config,
this would not get picked up in a config reload.  This patch fixes that
by resetting it in set_peer_defaults().

Closes ASTERISK-19454
Review: https://reviewboard.asterisk.org/r/3065/
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Merged revisions 403634 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 403635 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 403639 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@403652 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -30413,6 +30413,10 @@ static void set_peer_defaults(struct sip_peer *peer)
 	peer->disallowed_methods = sip_cfg.disallowed_methods;
 	peer->transports = default_transports;
 	peer->default_outbound_transport = default_primary_transport;
+	if (peer->outboundproxy) {
+		ao2_ref(peer->outboundproxy, -1);
+		peer->outboundproxy = NULL;
+	}
 }
 
 /*! \brief Create temporary peer (used in autocreatepeer mode) */