[SFTP]优化文件监听的逻辑。
[SFTP]修复提示框在MacOSX无法至顶的缺憾。
[SFTP]清理不再需要的缓存文件。
更换应用图标
[RDP]修复4K屏下，默认非智能拉伸登录远程桌面时，底部出现的空白块问题。
[SFTP] Optimize the logic of file monitoring.
[SFTP] Fixed the bug that the prompt box cannot be topped on Mac OS X.
[SFTP] Clean up cached files that are no longer needed.
Replace the application icon
[RDP] Fixed the blank block issue that appears at the bottom when logging into remote desktop with default non-intelligent stretch under 4K screen.