MGCP_Test: avoid crash in latest (TC_one_crcx_loopback_rtp_implicit)

The testcase TC_one_crcx_loopback_rtp_implicit triggers a bug in older
osmo-mgw version that eventually leads into a crash of osmo-mgw. This
also means that all tests after TC_one_crcx_loopback_rtp_implicit will
also fail. Lets move TC_one_crcx_loopback_rtp_implicit to the end of the
control section to postpone the crash to the very end of the testrun.

Change-Id: I25abf30f8c49e580c46e7a61e887bd0add9a4cd4
Related: OS#5123
diff --git a/mgw/MGCP_Test.ttcn b/mgw/MGCP_Test.ttcn
index c1e263a..307f0a8 100644
--- a/mgw/MGCP_Test.ttcn
+++ b/mgw/MGCP_Test.ttcn
@@ -2445,7 +2445,6 @@
 		execute(TC_one_crcx_receive_only_rtp());
 		execute(TC_one_crcx_loopback_rtp());
 		execute(TC_one_crcx_loopback_rtp_ipv6());
-		execute(TC_one_crcx_loopback_rtp_implicit());
 		execute(TC_two_crcx_and_rtp());
 		execute(TC_two_crcx_and_rtp_bidir());
 		execute(TC_two_crcx_diff_pt_and_rtp());
@@ -2474,5 +2473,11 @@
 		execute(TC_two_crcx_mdcx_and_rtp_osmux_ipv6());
 		execute(TC_two_crcx_mdcx_and_rtp_osmux_ipv4_ipv6());
 		execute(TC_two_crcx_mdcx_and_rtp_osmux_ipv6_ipv4());
+
+		/* Note: This testcase will trigger an OSMO_ASSERT() bug in
+		 * older versions of osmo-mgw. This eventually leads into
+		 * a failure of all subsequent testcases, so it is important
+		 * not to add new testcaes after this one. */
+		execute(TC_one_crcx_loopback_rtp_implicit());
 	}
 }