chan_sip: Always use fromdomain if set for domain, even if callerid is set to restricted.

(closes issue ASTERISK-20841)
Reported by: Kelly Goedert


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/1.8@411021 f38db490-d61c-443f-a65b-d21fe96a405b