bsc: Move hardcoded ip addr to variable

This way it's more clear what are those IP addresses for.

Change-Id: I3600fd0d0486205e5bdc487fa75e9038d3bfb52c
diff --git a/bsc/MSC_ConnectionHandler.ttcn b/bsc/MSC_ConnectionHandler.ttcn
index c709794..4436b0c 100644
--- a/bsc/MSC_ConnectionHandler.ttcn
+++ b/bsc/MSC_ConnectionHandler.ttcn
@@ -360,6 +360,8 @@
 	var MediaState g_media;
 	var TestHdlrParams g_pars;
 
+	var charstring host_bts := "127.0.0.2";
+	var charstring host_mgw := "127.0.0.3";
 	var boolean g_vty_initialized := false;
 }
 
@@ -878,7 +880,7 @@
 		codecType := FR_AMR;
 	}
 
-	f_MscConnHdlr_init(g_pars.media_nr, "127.0.0.2", "127.0.0.3", codecType);
+	f_MscConnHdlr_init(g_pars.media_nr, host_bts, host_mgw, codecType);
 
 	/* patch in the LCLS related items, as needed */
 	f_ass_patch_lcls(ass_tpl, exp_ass_cpl);