Map screenshots need to be updated, there are Nexuiz old items in these images

Map screenshots need to be replaced, there are old Nexuiz items in these pictures, so no longer covers Xonotic official artwork. Due to the changes that will go through the new powerups in xonotic-data.pk3dir!1096 and some asset changes were done 8 years ago.

Boil: xonotic-maps.pk3dir/maps/boil.jpg	Bromine: xonotic-maps.pk3dir/maps/bromine.jpg	Catharsis: xonotic-maps.pk3dir/maps/catharsis.jpg	Dance: xonotic-maps.pk3dir/maps/dance.jpg

Silensiege: xonotic-maps.pk3dir/maps/silentsiege.jpg	Vorix: xonotic-maps.pk3dir/maps/vorix.jpg