SAC documentation: don't specify transports for endpoints and registrations

Removing explicit transport definition for endpoints and registrations. It
isn't necessary and isn't generally advised.

ASTERISK-26514 #close

Change-Id: Ifdec5e631962438a4683600968dfa4bfd15909fb

configs/basic-pbx/pjsip.conf

@@ -15,7 +15,6 @@ bind = 0.0.0.0
 
 [dcs-trunk]
 type = registration
-transport = transport-udp-nat
 outbound_auth = dcs-trunk-auth
 server_uri = sip:sip.digiumcloud.net
 ;client_uri = sip:myaccountID@sip.digiumcloud.net
@@ -31,7 +30,6 @@ auth_type = userpass
 
 [dcs-endpoint]
 type=endpoint
-transport = transport-udp-nat
 context = DCS-Incoming
 allow = !all,g722,ulaw
 outbound_auth = dcs-auth
@@ -59,7 +57,6 @@ endpoint = dcs-endpoint
 ; Our primary endpoint template for internal desk phones.
 [endpoint-internal-d70](!)
 type = endpoint
-transport = transport-udp-nat
 context = Long-Distance
 allow = !all,g722,ulaw
 direct_media = no