Changes

mgcp_test: add CRCX for IUFP in sendrecv

Note, there are also ttcn3 tests sending the same to osmo-mgw being
submitted along with these patches, and the ttcn3 tests currently fail:
osmo-mgw rejects the connection mode "sendrecv" in the first CRCX.

Change-Id: Icdb1085b8e44ac4cff6c457163349b81e81bf765