_eab_wpdb_filter_postmeta_query () isn't cleared properly

the filter isn't properly cleared and gets in the way of $wpdb queries with LIMIT and no GROUP BY statements.

here's my fix (added a proper filter clear on the function)

#default-filters.php
function _eab_filter_meta_query ($check) {
add_filter('query', '_eab_wpdb_filter_postmeta_query');
remove_filter('query', '_eab_wpdb_filter_postmeta_query');
return $check;
}
add_filter('get_post_metadata', '_eab_filter_meta_query');