fix: nil bug

pkg/mqtt/connection.go

@@ -205,10 +205,11 @@ func (c *Connection) RcvMsgFromClient() {
 				return
 			}
 			args := rpcs.ArgsGetOnline{
-				Id:                device.DeviceIdentifier,
-				ClientIP:          host,
-				AccessRPCHost:     server.GetRPCHost(),
-				HeartbeatInterval: uint32(c.KeepAlive),
+				Id:            device.DeviceIdentifier,
+				ClientIP:      host,
+				AccessRPCHost: server.GetRPCHost(),
+				//HeartbeatInterval: uint32(c.KeepAlive),
+				HeartbeatInterval: 60000,
 			}
 
 			c.Mgr.AddConn(c.DeviceCode, c)