Add known internal IP address when autodomain=yes

(closes issue #14573)
Reported by: pj
Patches: 
      sip-internip-autodomain1.diff uploaded by mnicholson (license 96)
	modified by oej
Tested by: pj



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@215891 65c4cc65-6c06-0410-ace0-fbb531ad65f3