Revert "mgcp_ratectr: add stats items to monitor trunk usage"

This reverts commit 6bad138c96ef0e2a93ef7de42e897880131c0b43.

Reason for revert: heap-use-after-free during 'make check'
in mgcp_test.c test_retransmission()

Change-Id: I96792a719c9c7273676ab9ffe0b9e2aae4c23166
Related: OS#5201
6 files changed