Fix Segfault When Registering SIP Over WebSockets

The helper function, get_address_family_filter, in chan_sip for dns resolution
by address family was not recognizing the websockets transport and resulting in
a null pointer being sent to functions in netsock2, in an attempt to determine
if we are bound to ANY address ([::]) or not.

This patch fixes this issue by handling the transport types SIP_TRANSPORT_WS and
SIP_TRANSPORT_WSS which results in a sock address being set properly for use in
determining the address family.

(closes issue ASTERISK-20221)
Reported by: Sven Beisiegel
Tested by: Sven Beisiegel, James Mortensen
Patches: 
asterisk-20221-ws-family-filter.diff uploaded by Michael L. Young (license 5026)
........

Merged revisions 371295 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@371296 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -27596,11 +27596,9 @@ int get_address_family_filter(unsigned int transport)
 
 	if ((transport == SIP_TRANSPORT_UDP) || !transport) {
 		addr = &bindaddr;
-	}
-	else if (transport == SIP_TRANSPORT_TCP) {
+	} else if (transport == SIP_TRANSPORT_TCP || transport == SIP_TRANSPORT_WS) {
 		addr = &sip_tcp_desc.local_address;
-	}
-	else if (transport == SIP_TRANSPORT_TLS) {
+	} else if (transport == SIP_TRANSPORT_TLS || transport == SIP_TRANSPORT_WSS) {
 		addr = &sip_tls_desc.local_address;
 	}