msc: Make 'show msc' show the primary msc connection again

Revert an accidental change when introducing show mscs. We want
show msc to be like it was before.
diff --git a/src/vty_interface_cmds.c b/src/vty_interface_cmds.c
index 8697961..6f8ca05 100644
--- a/src/vty_interface_cmds.c
+++ b/src/vty_interface_cmds.c
@@ -106,15 +106,19 @@
       "show msc",
       SHOW_STR "Display the status of the MSC\n")
 {
-	struct msc_connection *msc;
+	struct msc_connection *msc = msc_connection_num(bsc, 0);
 
-	llist_for_each_entry(msc, &bsc->mscs, entry) {
-		vty_out(vty, "MSC link is %s and had %s.%s",
-			msc->msc_link_down == 0 ? "up" : "down",
-			msc->first_contact == 1 ? "no contact" : "contact",
-			VTY_NEWLINE);
+	if (!msc) {
+		vty_out(vty, "%%No MSC Connection defined in this app.%s", VTY_NEWLINE);
+		return CMD_WARNING;
 	}
 
+
+	vty_out(vty, "MSC link is %s and had %s.%s",
+		msc->msc_link_down == 0 ? "up" : "down",
+		msc->first_contact == 1 ? "no contact" : "contact",
+		VTY_NEWLINE);
+
 	return CMD_SUCCESS;
 }