bsc CBSP: fix TC_cbsp_write_lai

bts 2 matches the described scenario, not bts 0.

Change-Id: If8408df207176704db0d0ce9d75ae13d500d31ae
diff --git a/bsc/BSC_Tests_CBSP.ttcn b/bsc/BSC_Tests_CBSP.ttcn
index 20006dc..b079347 100644
--- a/bsc/BSC_Tests_CBSP.ttcn
+++ b/bsc/BSC_Tests_CBSP.ttcn
@@ -501,11 +501,15 @@
 testcase TC_cbsp_write_lai() runs on cbsp_test_CT {
 	var CBSP_IEs pages := {f_gen_page()};
 	var template (value) BSSMAP_FIELD_CellIdentificationList cell_list;
-	cell_list := ts_BSSMAP_CIL_LAI({bssmap_lai(mp_cgi_bts0)});
+	/* bts0 and bts1 have the same LAI (only differ in cell identity).
+	 * bts2 and bts3 also have the same LAI, but only bts2 has a CBCH.
+	 * Target only bts2.
+	 */
+	cell_list := ts_BSSMAP_CIL_LAI({bssmap_lai(mp_cgi_bts2)});
 	f_cbsp_init_server(7001, 7501);
 	f_cbsp_write(g_cbsp_msg_id, g_cbsp_ser_no, cell_list, content:=pages,
 		     success_list:=?, fail_list:=omit);
-	IPA_RSL[0].receive(tr_ASP_RSL_UD(f_page2rsl(pages[0], g_cbsp_msg_id, g_cbsp_ser_no)));
+	IPA_RSL[2].receive(tr_ASP_RSL_UD(f_page2rsl(pages[0], g_cbsp_msg_id, g_cbsp_ser_no)));
 	f_sleep(5.0);
 }