Add missing 'version' param to get WMS legends (ref #11)

[marcantoinedupre]

Here is a one-line fix to add the missing version param to WMS GetLegendGraphic requests (solves #11). The value passed is the one from Leaflet (default or overridden value).

According to the spec:

The VERSION parameter is mandatory in requests other than GetCapabilities.

OpenGIS Web Map Service (WMS) Implementation Specification, p. 11.

And some map servers enforce this, as the WMSServer component of an Arcgis server.

It would be awesome if you could merge it and release! 🙏

[marcantoinedupre]

I have updated my fix. The version value is at layer.wmsParams.version, previously I thought it was layer.version. (The latter still solved my issue: it used to pass the query param version=undefined with GetLegendGraphic and the map server happily accepted it :D )

[marcantoinedupre]

Any news on this? @ignaciofagian @dandormont

[dandormont]

Sorry I'm not the maintainer here. I just happen to have contributed some minor fixes. I'm also not all that familiar with WMS to be perfectly honest 🤔