GTP_Templates: Fix several template type incongruencies

This fixes following error while running test
GGSN_Tests.TC_pdp46_act_deact_apn4:

"GTP_Templates.ttcn:315 Dynamic test case error: Restriction `omit' on
template of type octetstring violated."

Change-Id: I3846d2a077e4bc53a772e354fcc3c38ca952b38f
1 file changed