Remove unnecessary close (it could cause another hang)

Author: tvhung83

src/main/java/org/embulk/output/sftp/SftpLocalFileOutput.java

@@ -135,7 +135,6 @@ public void finish()
     public void close()
     {
         closeCurrentFile();
-        closeRemoteFile();
         // TODO
         sftpUtils.close();
     }