bsc: TC_assignment_csd: delete mgcp EP after clear

Fix the test for sccplite, where it fails at the third rate with:
  Crit already present{ connid := omit, endpoint := omit, transid := omit }

For each rate that gets tested, a new expectation (Crit) gets set by
f_tc_assignment_csd() (f_establish_fully() -> f_create_mgcp_expect()).

If the expectation already exists at this point, it leads to the error
above. While the rate gets tested, the expectation gets removed in
MGCP_Emulation:main() (ops.create_cb.apply -> ExpectedCreateCallback()),
but only if the EP is not known.

So without this patch:
* T_14k4: passes, EP is not known, Crit gets removed
* T_9k6: passes, EP is known, Crit does not get removed
* T_4k8: error, because Crit already exists

Related: OS#4393
Change-Id: Ib8d27a670931105f45b994799c4757fffabdf97d
---
M bsc/BSC_Tests.ttcn
1 file changed, 27 insertions(+), 0 deletions(-)

diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 5e739b2..3861f34 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -1875,6 +1875,7 @@
 	}
 
 	f_perform_clear();
+	f_create_mgcp_delete_ep(g_media.mgcp_ep);
 }
 private function f_tc_assignment_csd_all(charstring id) runs on MSC_ConnHdlr {
 	/* Data rates that require multi-slot HSCSD assignment are not tested

