Tooltip length label incorrect

If I set UOM=2 on the shortcode, when I put my mouse pointer at the chart, the tooltip should give a unit ‘km’ on the length and ‘m’ on the altitude. In the current version, it gives ‘m’ as the unit on both cases.

For a quick fix, I changed WP-GPX-Maps.js line 1217 :-
from
_formats.push( l_y );
to
_formats.push( l_x );

Not sure if this is the right way to do but I always use UOM 2 so it works for me ^_^