Fix FTP support
Originally created by Tails on #6096 (Redmine)
In Tails 0.12.1, I manage to connect to a FTP server on the Internet
ftp.de.debian.org) neither with iceweasel nor with GNOME
"Connect to server" feature.
At least the latter works properly to connect to a FTP server on the LAN by IP.
- Related to #16710 (closed)