Ticket 47521 - Complex filter in a search request doen't work as expected.
    
    Bug Description:  Before the search is executed there is the attempt to simplify filters.
    	eg a filter like (&(&(a=x))(&(b=y))) it is reduced to (&(a=x)(b=y)).
    	but if there is a simple filter between complex filters it is lost
    	eg (&(&(a=x))(c=z)(&(b=y))) is also transformed to (&(a=x)(b=y)).
    
    Fix Description:   if a simple filter is processed and there was a previous complex filter
    	flattend, insert the simple filter properly
    
    https://fedorahosted.org/389/ticket/47521
    
    Reviewed by: richM, thanks