gnome.bbclass: remove unneeded scrollkeeper stuff from gnome packages.

gnome.bbclass: remove unneeded scrollkeeper stuff from gnome packages.

Scrollkeeper generates its XML database for every package when
installing it. The problem is that while building it sees only specific
package scrollkeeper stuff so we get wrong scrollkeeper xml file
generated for every gnome.bbclass package. Including the file into every
gnome package results in package contents conflicts.

This patch removes a quick hack made by Koen with previous commit.

Signed-off-by: Ihar Hrachyshka <ihar.hrachyshka@gmail.com>
Acked-by: Phil Blundell <philb@gnu.org>
Signed-off-by: Koen Kooi <koen@openembedded.org>