a00c1d4 LDAP: Fix saving empty groups

Authored and Committed by jhrozek 7 years ago
    LDAP: Fix saving empty groups
    
    https://fedorahosted.org/sssd/ticket/1647
    
    A logic bug in the LDAP provider causes an attempt to allocate a zero-length
    array for group members while processing an empty group. The allocation
    would return NULL and saving the empty group would fail.