fix：修改订阅主题

ruoyi-modules/ruoyi-hazard/src/main/java/org/dromara/hazard/handler/HazardMqttMessageHandler.java

@@ -102,9 +102,9 @@ public class HazardMqttMessageHandler implements MqttMessageHandler {
     public void subscribeTopics() {
         try {
             // 订阅一个主题，QoS=1
-            mqttGateway.subscribe("iot-hazard-server", 1);
+            mqttGateway.subscribe("iot_hazard_server", 1);
             mqttGateway.subscribe("status/online", 1);
-            log.info("危险源模块已订阅MQTT主题: iot-hazard-server");
+            log.info("危险源模块已订阅MQTT主题: iot_hazard_server");
         } catch (Exception e) {
             log.error("订阅MQTT主题失败", e);
         }