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
diff --git a/include/osmocom/mgcp/mgcp_trunk.h b/include/osmocom/mgcp/mgcp_trunk.h
index d960428..048ac5b 100644
--- a/include/osmocom/mgcp/mgcp_trunk.h
+++ b/include/osmocom/mgcp/mgcp_trunk.h
@@ -52,9 +52,8 @@
 	unsigned int number_endpoints;
 	struct mgcp_endpoint **endpoints;
 
-	/* rate counters and stat items to measure the trunks overall performance and health */
+	/* global rate counters to measure the trunks overall performance and health */
 	struct mgcp_ratectr_trunk ratectr;
-	struct mgcp_stat_trunk stats;
 
 	union {
 		/* Virtual trunk specific */