x11/gnome-terminal: upgrade to 3.54.4

Upgrade to latest version to fix the build of the nautilus extension
with latest nautilus.
While here remove the SEARCHPROVIDER option, the option is only to
install a simple ini file, and add run time dependency, which are
actually not useful, the same way we now always completion files
regardless weather or not a shell is installed, gnome-shell users will
be happy to see the search provider is always configured for
gnome-terminal.