MGCP_Test: Test non LCO crcx

When a CRCX without an LCO option (codec) is sent, then older versions
of osmo-mgw will omit the port number in the SDP part of the response.
Also no default codec is selected and reported back. This testcase
pinpoints the problem.

Change-Id: Ie16cdab936ce468fe378d4ec9e1c61f81c07fb4e
Related: OS#2658
3 files changed