Set RU 0 to master and others to slave. Testing the synch

targets/RT/USER/lte-ru.c

@@ -2199,6 +2199,7 @@ void init_RU(char *rf_config_file) {
     ru->rf_config_file = rf_config_file;
     ru->idx          = ru_id;              
     ru->ts_offset    = 0;
+    ru->is_slave     = (ru_id == 0) ? 0 : 1;
     // use eNB_list[0] as a reference for RU frame parameters
     // NOTE: multiple CC_id are not handled here yet!