confdb: Check for config file errors on sssd startup
Resolves:
https://fedorahosted.org/sssd/ticket/2028
Signed-off-by: Lukas Slebodnik <lslebodn@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>