Support choice of sip or sips scheme for outbound gateway using TLS

[davehorton]

Currently when we add an outbound gateway we can choose the protocol, as per below:

However, when we choose TLS or TLS/SRTP we always then use the "sips" scheme. This signifies end-to-end encryption. Some carriers though, because they are only using encryption on the leg of the call to us, either prefer or require that we use the "sip" scheme.

Therefore, we need an additional checkbox on outbound gateways that is labeled "Use sips scheme". If not checked, we should default to using "sip", both if/when registering and sending OPTIONS pings as well as outbound calls

[mercuryyy]

The - jambonz/sbc-outbound#136

Does not fix the above issue.

[xquanluu]

Hi @mercuryyy

I'm sorry that I missed your comment, could you please attach some log or tell us how to reproduce the issue?