Make transfer not ignore port information with SIP.

Make transfer not ignore port information with SIP.

Attempting to transfer with SIP to an address like 1XXXXX@ip.ad.re.ss:5061 would fail
because port would be cut from the host string and ignored. This simply keeps chan_sip
from cutting off the port number during these kinds of transfers.

(closes issue ASTERISK-19321)
Reported by: Federico Alves
Review: https://reviewboard.asterisk.org/r/1790/diff/#index_header
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Merged revisions 358643 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 358644 from http://svn.asterisk.org/svn/asterisk/branches/10

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@358645 65c4cc65-6c06-0410-ace0-fbb531ad65f3