ftp/net2ftp: Update to 1.4

Changes:
- net2ftp is now compatible with PHP version 8
- The Java upload applet has been removed, as applets are not supported any
  longer in Firefox and Chrome
- The CKEditor has been removed, as the latest version 5 build 25.0.0 inserts
  strange symbols into the text
- The jQuery libraries are now loaded from Google, and only on the pages where
  they are required (to improve page loading times)
- Thanks to php-download.com for providing a ready to use version of phpseclib.