Web Route Planner: Calculate statistics of imported tracks

Right now if importing a GPX-track WITHOUT elevation data, just "Total Distance" (and maybe "Total time") is calculated. Web Route Plannner seems to not assign elevation values to the track points. So all elevation statistics is "0".

Please add an option to assign (for tracks without elevation data) and alternative update (for tracks with wrong elevation data) elevation data to tracks and calculate/update its elevation statistics.