config: Allow timeout for all sevices
Allow option "timeout" for all sevices.
Also remove unused macro CONFDB_SERVICE_TIMEOUT.
Resolves:
https://fedorahosted.org/sssd/ticket/3068
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
(cherry picked from commit 1b9b5477027d86a2afb2e72981253d108c5398da)