Define icon-shadow only in context of icon-white
Define icon-shadow only in context of icon-white

Signed-off-by: Marin Treselj <52d9a2cc899a8db7044d09f9abec336fb5fb7086@pixelipo.com>

andreas-p/nextcloud-server,andreas-p/nextcloud-server,andreas-p/nextcloud-server,nextcloud/server,michaelletzgus/nextcloud-server,nextcloud/server,michaelletzgus/nextcloud-server,nextcloud/server,andreas-p/nextcloud-server,michaelletzgus/nextcloud-server,andreas-p/nextcloud-server,michaelletzgus/nextcloud-server,nextcloud/server