sudo: always use srv_opts from id context
Prior this patch, we remember id_ctx->srv_opts in sudo request to switch
the latest usn values. This works fine most of the time but it may cause
a crash.
If we have two concurrent sudo refresh and one of these fails, it causes
failover to try the next server and possibly replacing the old srv_opts
with new one and it causes an access after free in the other refresh.
Resolves:
https://pagure.io/SSSD/sssd/issue/3562
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>