spec file: depend on Dogtag 10.2.6-12 for tomcat 8 upgrade
Dogtag 10.2.6-12 includes automatic upgrade from Tomcat 7 to Tomcat 8.
Otherwise FreeIPA is broken after upgrades. This affects Fedora 22 to
Fedora 23 upgrades.
https://bugzilla.redhat.com/show_bug.cgi?id=1274915
Reviewed-By: Petr Vobornik <pvoborni@redhat.com>