ftmod_libpri: temporary segfault fix if libpri does not have BRI support

libs/freetdm/src/ftmod/ftmod_libpri/ftmod_libpri.c

@@ -1100,10 +1100,16 @@ static void *ftdm_libpri_run(ftdm_thread_t *me, void *obj)
 		case FTDM_TRUNK_BRI:
 			res = lpwrap_init_bri(&isdn_data->spri, span, isdn_data->dchan,
 					isdn_data->pswitch, isdn_data->node, 0, isdn_data->debug);
+#ifndef HAVE_LIBPRI_BRI
+			goto out;
+#endif
 			break;
 		case FTDM_TRUNK_BRI_PTMP:
 			res = lpwrap_init_bri(&isdn_data->spri, span, isdn_data->dchan,
 					isdn_data->pswitch, isdn_data->node, 1, isdn_data->debug);
+#ifndef HAVE_LIBPRI_BRI
+			goto out;
+#endif
 			break;
 		default:
 			snprintf(span->last_error, sizeof(span->last_error), "Invalid trunk type");