LDAP: Removing of member link from group
Resolves:
https://fedorahosted.org/sssd/ticket/2940
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
(cherry picked from commit e0903f41922721edf292a9f7e6605a4519db53a1)