BSC_Tests: fix DTE in TC_lost_sdcch_during_assignment()

This test case fails in ttcn3-bsc-test-sccplite due to:

  BSC_Tests.ttcn:10212 Dynamic test case error:
    Using the value of an optional field containing omit.

Change-Id: I235027c2b53b8f2ae975e25eb7c38b1959668d6f
Related: SYS#5627
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index ad8f666..f602929 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -10311,11 +10311,9 @@
  * Activ Ack (SYS#5627). */
 private function f_TC_lost_sdcch_during_assignment(charstring id) runs on MSC_ConnHdlr {
 	var PDU_BSSAP ass_cmd := f_gen_ass_req();
-	if (mp_bssap_cfg[0].transport == BSSAP_TRANSPORT_AoIP) {
-		ass_cmd.pdu.bssmap.assignmentRequest.codecList := g_pars.ass_codec_list;
-	}
-	ass_cmd.pdu.bssmap.assignmentRequest.channelType :=
-				f_BSSMAP_chtype_from_codec(g_pars.ass_codec_list.codecElements[0]);
+
+	ass_cmd.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
+	ass_cmd.pdu.bssmap.assignmentRequest.codecList := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
 
 	var BSSMAP_FIELD_CodecType codecType;
 	codecType := valueof(ass_cmd.pdu.bssmap.assignmentRequest.codecList.codecElements[0].codecType);
@@ -10389,7 +10387,6 @@
 	f_init(1, true);
 	f_sleep(1.0);
 
-	pars.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
 	vc_conn := f_start_handler(refers(f_TC_lost_sdcch_during_assignment), pars);
 	vc_conn.done;