Ticket 49064 - RFE allow to enable MemberOf plugin in dedicated consumer
    
    Bug Description:
    	memberof triggers some internal updates to add/del 'memberof' values.
    	on a readonly consumer, those updates selects a REFERRAL_ON_UPDATE backend
    	and that is not followed by internal updates.
    	At the end of the day, the update is rejected and if memberof plugin is enabled
    	replication will stuck on that rejected update
    
    Fix Description:
    	internal updates from memberof need to bypassing referrals.
    	So they flag internal updates SLAPI_OP_FLAG_BYPASS_REFERRALS, so that mtn_get_be
    	(mapping tree selection) will not return the referrals.
    
    https://pagure.io/389-ds-base/issue/49064
    
    Reviewed by: Ludwig Krispenz, William Brown (thanks a LOT !)
    
    Platforms tested: F23 (all tickets + basic suite)
    
    Flag Day: no
    
    Doc impact: no