Add build dependency for libaskuser-notification to askuser

Add build dependency for libaskuser-notification to askuser

Although askuser doesn't need libaskuser-notification for now, it build
depends on libsecurity-manager-client, which is linked against
libaskuser-notification.
Such dependency should be resolved automatically by gbs, but it's not for
some reason. Probably gbs doesn't handle too well dependencies between
two spec files built from single repository.

Adding this dependency manually. It will be need anyway soon, when askuser
original functionality is restored for run-time pop-ups.

Change-Id: Ief4084d90094070e609d21575aee246acb747f4a
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>