Treat UPGs correctly in winsync replication
    
    IPA winsync plugin failed to replicate users when default user group
    was non-posix even though User Private Groups (UPG) were enabled
    on the server. Both their uidNumber and gidNumber were empty and
    they missed essential object classes. When the default user group
    was made posix and UPG was disabled it did not set gidNumber to
    the default group gidNumber.
    
    This patch improves this behavior to set gidNumber correctly
    according to UPG configuration and the default group status
    (posix/non-posix). 4 situations can occur, the following list
    specifies what value is assigned to user gidNumber:
     1) Default group posix, UPG enabled: gidNumber = UPG gidNumber
     2) Default group posix, UPG disabled: gidNumber = default
        group gidNumber
     3) Default group non-posix, UPG enabled: gidNumber = UPG gidNumber
     4) Default group non-posix, UPG disabled: an error is printed to
        the dirsrv log as the gidNumber cannot be retrieved. User
        is replicated in the same way as before this patch, i.e.
        without essential object classes.
    
    https://fedorahosted.org/freeipa/ticket/2436