Revert partial of 0ac6315212a3 ("msc: add inter-BSC and inter-MSC Handover tests")

Commit 0ac6315212a breaks all related GSUP SS tests because it require
all GSUP SS packages to have a OSMO_GSUP_MESSAGE_CLASS_USSD IE.

Change-Id: Iadbc37105fa67cf6383fb63b86ed653ccc7bddf7
1 file changed