Remove plus sign from GTK
GTK's plus sign was removed in 2019: https://www.mail-archive.com/gtk-devel-list@gnome.org/msg19090.html GNOME/gtk@d080be3e
GTK's plus sign was removed in 2019: https://www.mail-archive.com/gtk-devel-list@gnome.org/msg19090.html GNOME/gtk@d080be3e