Call should use local IP in Via sent-by when the account not using STUN

[nanang]

Reported that when STUN is configured (globally) and an account is configured to not use STUN, the outgoing REGISTER message uses local IP, but the outgoing INVITE uses mapped/public IP in its Via "sent-by" value. For some server, this is unacceptable and the INVITE is silently discarded.

Thanks Chris Updegraft for the report.

Moreover, ticket #1412 specifies:

Initial Via "sent-by" value now will be affected by STUN setting in the account. If it is disabled, local IP will be used.

and r4229 in the ticket handles presence subscription, publish, and MWI, but strangely not call, so this ticket will handle call.

[nanang]

In 4963:

Fix #1804: Call should use local IP in Via sent-by when the account is not using STUN.