fixes an issue with clock source

- command line paramter --clock-source can only be set at UE (removed this option from gNB)
 - at gNB use clock_source from RU section in config file
 - in both cases if clock_source is present in usrp_args, it will override clock_source

executables/nr-ru.c

@@ -2252,6 +2252,9 @@ void RCconfig_RU(void)
           LOG_E(PHY, "Erroneous RU clock source in the provided configuration file: '%s'\n", *(RUParamList.paramarray[j][RU_SDR_CLK_SRC].strptr));
         }
       }
+      else {
+	RC.ru[j]->openair0_cfg.clock_source = unset;
+      }
 
       if (strcmp(*(RUParamList.paramarray[j][RU_LOCAL_RF_IDX].strptr), "yes") == 0) {
         if ( !(config_isparamset(RUParamList.paramarray[j],RU_LOCAL_IF_NAME_IDX)) ) {