Taxonomy: Don't pass results of 'count' query through 'get_terms' filter.
Use of the 'get_terms' filter was consolidated in , with the
introduction of WP_Term_Query. At that time, the result of 'count=true'
queries began being filtered by 'get_terms'. This breaks existing 'get_terms'
callbacks, which often assume that the returned value will be an array or a WP_Error object.