修复单线程下载时，文件已经完成，重复下载回调下载失败的问题

修复一个重新下载文件时，同名路径文件没有被被删除的问题

HttpComponent/src/main/java/com/arialyy/aria/http/download/HttpDTTBuilderAdapter.java

@@ -35,10 +35,13 @@ final class HttpDTTBuilderAdapter extends AbsNormalTTBuilderAdapter {
     BufferedRandomAccessFile file = null;
     try {
       if (totalThreadNum > 1 && !record.isBlock) {
-        file = new BufferedRandomAccessFile(new File(getTempFile().getPath()), "rwd", 8192);
+        file = new BufferedRandomAccessFile(getTempFile().getPath(), "rwd", 8192);
         //设置文件长度
         file.setLength(getEntity().getFileSize());
       }
+      if (getTempFile().exists()) {
+        FileUtil.deleteFile(getTempFile());
+      }
       return true;
     } catch (IOException e) {
       e.printStackTrace();