Fix a bug in SRV lookups where dnsmgr would discard everything but the

first SRV result from DNS before processing weights and priorities and 
dns_parse_answer wouldn't report that there were no records in DNS 
unless a failure occured. Also fixed a bug where dnsmgr_refresh would 
report that a entry was being changed when ast_gethostbyname had failed.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@129156 65c4cc65-6c06-0410-ace0-fbb531ad65f3