Simplicity

Results 2 issues of Simplicity

![Screenshot 2024-03-10 at 23 09 53](https://github.com/mpetazzoni/leaflet-gpx/assets/10195471/21a3a492-cdae-494c-bce9-c0f305505d89) The track shows successfully however the points aren't mapped accurately. There is a consistent offset. I have tried multiple GPX files from different sensors...

The map itself shows up fine, but the track does not. My console is showing the following issue: ``` Uncaught TypeError: Cannot read properties of undefined (reading '_container') at i._addToChartDiv...