Fix SearchWP and Woocomerce integration for default search page

<?php
add_filter( 'facetwp_is_main_query', function( $is_main_query, $query ) {
    if ( $is_main_query && $query->is_main_query() && $query->is_search() ) {
        if ( true == $query->get( 'wc_query' ) ) {
            $query->set( 'using_searchwp', '' );
        }        
    }
    return $is_main_query;
}, 11, 2);