Major bug with destination address calculation for strict route set (thanks Hoi-Ho Chan)

[bennylp]

The destination address of a request is calculated by pjsip_get_request_addr() function in sip_util.[hc] file. For strict-route case, this function will remove the top-most Route, put this Route URI into target URI, and place the original target URI as the last Route header.

When there is only one strict Route header present, effectively this will swap the value of Route URI with the request URI.

The problem occurs because this function was called twice by the transaction, first during UAC transaction initialization and second when sending the request. Because of this, on the second call of the function, the function will swap back the Route and request URI, putting back the Route and request URI of the original request'''