Ticket 48844 Regression introduced in matching rules by DS 48746
    
    Bug Description:
        Old style MR plugin (like bitwise, collation) register their own indexer function.
    
        new style MR plugin just use the default_mr_indexer_create.
    
        When looking for a MR plugin that can handle a given OID we must look to old style and
        new style MR plugin.
    
        In the fix https://fedorahosted.org/389/ticket/48746, the code looking up into old style
        MR plugin has been erronously removed.
    
    Fix Description:
        Make sure that plugin_mr_filter_create looks up in old and new style MR
    
    https://fedorahosted.org/389/ticket/48745
    
    Reviewed by: William Brown (thanks William!)
    
    Platforms tested: F23
    
    Flag Day: no
    
    Doc impact: no