Currently, the DNS resolver will allow sip:<ip-address> to resolve to UDP,
TCP, or TLS, in that order of priority. In some cases it may be desirable to
disable everything but UDP in this situation, so this patch allows this
behavior to be configured.


git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10829 ddefafc4-47db-0310-ae44-fa13212b10f2