Changes

STP_Tests_TCAP: Fix ipa_to_ipa testcase

tcap routing doesn't work the way the test thinks. E.g. a Begin can't be
routed to a special destination because it does't contain a dtid which
is needed to route to the correct ASP.

Change-Id: Ie274232b706348b5ab6d0ac248883d86c53ebb4e