As per ESC & Design Team decisions.

It has become unusable anyway after major changes
on the Mozilla side.

Long live Libreoffice Themes! :)

Change-Id: I2893fbc5e4f5637ee9715fa426b92ca58534f126
Reviewed-on: https://gerrit.libreoffice.org/72811
Tested-by: Jenkins
Reviewed-by: Julien Nabet <serval2412@yahoo.fr>
Reviewed-by: Heiko Tietze <tietze.heiko@gmail.com>
Reviewed-by: Muhammet Kara <muhammet.kara@collabora.com>