doc: 修复注释错误 (#297)

jetlinks-manager/device-manager/src/main/java/org/jetlinks/community/device/message/DeviceMessageConnector.java

@@ -146,11 +146,11 @@ public class DeviceMessageConnector implements DecodedClientMessageHandler {
             if (event.isClusterExists()) {
                 return Mono.empty();
             }
-            //从会话管理器里监听会话注册,转发为设备上线消息
+            //从会话管理器里监听会话注销,转发为设备离线消息
             if (event.getType() == DeviceSessionEvent.Type.unregister) {
                 return handleSessionMessage(new DeviceOfflineMessage(),event.getSession());
             }
-            //从会话管理器里监听会话注销,转发为设备离线消息
+            //从会话管理器里监听会话注册,转发为设备上线消息
             if (event.getType() == DeviceSessionEvent.Type.register) {
                 return handleSessionMessage(new DeviceOnlineMessage(),event.getSession());
             }