Description of problem:
LDAP specification says that minutes and seconds might be omitted and in that
case these are meant to be treated as zeros [1].

When sudo rule defines sudoNotAfter and/or sudoNotBefore options which are
defined upto hours, e.g. 2019103116Z, sssd does not match the rule and refuses
a user to run a command. If the options are padded by zeros, e.g.
20191031160000Z it works.

SSSD shoudl behave according to the LDAP specifications in this terms.

Version-Release number of selected component (if applicable):
sssd-2.2.0-19.el8.x86_64

How reproducible:
100%

Steps to Reproduce:
1. have a rule with sudoNotBefore set to the past but specified upto hours,
e.g. 2019103116Z
2. try to run command allowed by the rule

Actual results:
sudoNotBefore=2019103015Z
$ sudo -l
Sorry, user userallowed may not run sudo on ci-vm-10-0-137-224.

sudoNotBefore=20191030150000Z
$ sudo -l
Matching Defaults entries for userallowed on ci-vm-10-0-137-224:
    !authenticate, !requiretty

User userallowed may run the following commands on ci-vm-10-0-137-224:
    (root) NOTBEFORE=20191030150000Z ALL

Expected results:
sudoNotBefore=2019103015Z
$ sudo -l
Matching Defaults entries for userallowed on ci-vm-10-0-137-224:
    !authenticate, !requiretty

User userallowed may run the following commands on ci-vm-10-0-137-224:
    (root) NOTBEFORE=20191030150000Z ALL

sudoNotBefore=20191030150000Z
$ sudo -l
Matching Defaults entries for userallowed on ci-vm-10-0-137-224:
    !authenticate, !requiretty

User userallowed may run the following commands on ci-vm-10-0-137-224:
    (root) NOTBEFORE=20191030150000Z ALL


Additional info:
1. https://ldapwiki.com/wiki/GeneralizedTime