Ticket 50282 - OPERATIONS ERROR when trying to delete a group with automember members
    
    Bug Description:
    	When automember and memberof are enabled, if a user is member of a group
    	because of an automember rule. Then when the group is deleted,
    	memberof updates the member (to update 'memberof' attribute) that
    	trigger automember to reevaluate the automember rule and add the member
    	to the group. But at this time the group is already deleted.
    	Chaining back the failure up to the top level operation the deletion
    	of the group fails
    
    Fix Description:
    	The fix consists to check that if a automember rule tries to add a user
    	in a group, then to check that the group exists before updating it.
    
    https://pagure.io/389-ds-base/issue/50282
    
    Reviewed by: Mark Reynolds, William Brown
    
    Platforms tested: F29
    
    Flag Day: no
    
    Doc impact: no