修复任务未下载时，直接删除任务导致的注解回调方法中任务状态错误

https://github.com/AriaLyy/Aria/issues/123
，重试失败任务添加网络状态判断，网络未连接，将会重试失败
https://github.com/AriaLyy/Aria/issues/119

app/src/main/java/com/arialyy/simple/download/FtpDownloadActivity.java

@@ -35,9 +35,7 @@ import java.io.File;
  * Ftp下载测试
  */
 public class FtpDownloadActivity extends BaseActivity<ActivityFtpDownloadBinding> {
-  //private final String URL = "ftp://172.18.104.129:21/haha/large.rar";
-  //private final String URL = "ftp://172.18.104.129:21/haha/large.rar";
-  private final String URL = "ftp://172.18.104.66:21/haha/成都.mp3";
+  private final String URL = "ftp://192.168.8.2:21/test.apk";
 
   @Override protected void init(Bundle savedInstanceState) {
     super.init(savedInstanceState);