Fix calling parameters of Dot for PatternItem

[felix-engelmann]

This is a minor change fixing #1886. The Skanetrafiken app now is able to display footpaths. Thanks to @raminou who found the issue that the length argument must be of type Float.

Unfortunately I was not able to test the other apps affected by this issue (cf #1906)

Screenshot of the working view:

Zoomed in section of the footpath:

[thrillfall]

Thanks for providing a fix

[mar-v-in]

The length field in PatternItem is a Float (aka nullable) by now (e.g. in 0.3.0). Can you confirm you still see issues without this change?

[felix-engelmann]

The crash no longer happens, from which I assume it is fixed. The only problem remaining, is that the map is no longer zoomable/panable. I'll investigate this once I have more time.