INC3072676: remove deprecated ldap_initgroups_use_matching_rule_in_chain configuration option

These options are seldom used, therefore not very well tested (although we should ask our downstream QE colleagues if they are tested at all) and AFAIK don't really provide any benefit. It would simplify the code to just remove them.

ref: https://github.com/SSSD/sssd/issues/4518 and https://github.com/SSSD/sssd/commit/65bd6bf05d75c843e525f8bf89e9b75b02a2bfb7

sssctl config-check does not complain with this patch (which it did previously)