res_pjsip_transport_websocket: Attach the Websocket module on outgoing INVITEs.

res_pjsip_transport_websocket: Attach the Websocket module on outgoing INVITEs.

In order to alter the Contact header on in-dialog requests and responses the
Websocket module must be attached on outgoing INVITEs. The Contact header is
modified so that the PJSIP transport layer can find and use the existing
Websocket connection based on the source IP address, port, and transport.

ASTERISK-24143 #close
Reported by: Aleksei Kulakov

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@421955 65c4cc65-6c06-0410-ace0-fbb531ad65f3