When a device registers we need to unlink them (if linked) from the peers_by_ip conta...

When a device registers we need to unlink them (if linked) from the peers_by_ip container and link them back in since their IP address has changed. This would have manifested itself if you configured a new device (as type=peer), registered, and then tried to place a call from the device. Since the peer was not linked into the peers_by_ip container it would have never been found.
(closes issue #13811)
Reported by: pj

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@163629 65c4cc65-6c06-0410-ace0-fbb531ad65f3