DLMGCP message buffer to small, can not generate MGCP message

test_mgcp_client_cancel():
- composed msg with trans_id=1
- not in queue yet, cannot cancel yet
DLMGCP Cannot cancel, no such transaction: 1
- enqueue
- cancel succeeds
DLMGCP Canceled transaction 1
- late response gets discarded
DLMGCP Cannot find matching MGCP transaction for trans_id 1
- canceling again does nothing
DLMGCP Cannot cancel, no such transaction: 1
test_mgcp_client_cancel() done
Done