evcamera: apply_config revise

hi3518/main.cc

@@ -827,6 +827,7 @@ void handle_mqtt_req(MqttHelper *hlp, const void * const data, int len, string t
                     else {
                         /// TODO: using json diff to apply change without reboot
                         save_configuration(data);
+                        load_configuration(gJsonConfig);
                         if(needReboot) {
                             MqttMgr::report_response_args(gMqttClient, consts::pub_topic_response + rid, 0, "rebooting to apply new config", cmd, rid, data);
                             rlogger->info("rebooting to apply new configuration");