Merge remote-tracking branch 'origin/master'

ruoyi-common/ruoyi-common-mqtt/src/main/java/org/dromara/common/mqtt/server/MqttGateway.java

@@ -163,7 +163,7 @@ public class MqttGateway {
      * @param command 命令内容
      */
     public void sendCommand(String deviceCode, String command) {
-        String topic = "iot-hazard/" + deviceCode;
+        String topic = "iot_hazard/" + deviceCode;
         // 发布消息，QoS=1，不保留
         publish(topic, command, 1, false);
     }