Width CSS

I noticed that on line 629 of wp-gpx-maps.php, you re-use the $w variable for width for drawing the map div.

I believe this embedded div should be 100%, otherwise the container is 50%, and the map gets drawn as 50% of that, resulting in the map being 25% total width.

https://ww.wp.xz.cn/plugins/wp-gpx-maps/