Changes

Fix decoding of TCAP messages

asn1c would fail while decoding the DialoguePortion of a TCAP message
probably because Tag APPLICATION 11 is sent as constructed tag and the
WS adaptation expects a primitive one.

Support for EXTERNAL needs newer asn1c.

Related: SYS#7486
Change-Id: I4a27a52b2be70b1fc50e0a3d5441ded4c151fe65