to compile the translations (which is all what CI does) we need only a
minimal build of linguist.

Change-Id: Ide0a2c0a4dd3890054dbb00b01d5c2835615ff88
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>