Changes

ttcn3-stp-test: do not set mp_osmo_stp_newer_than_1_4_0

Setting a non-existing parameter makes TITAN unhappy:

  HC@fd91bc0a2114: Error while setting parameter field
                   'STP_Tests_M3UA.mp_osmo_stp_newer_than_1_4_0' to 'true':
                   Module parameter cannot be set, because no parameter with
                   name 'mp_osmo_stp_newer_than_1_4_0' exists in module
                   'STP_Tests_M3UA'.

Change-Id: Ie4fba3eb73e0da60bc20859efddecc5ec816cb9e