Cannot read property 'getSource' of null

[DailisLangovskis]

When loading layer from layman inside the draw toolbar!

[fzadrazil]

It happens even when trying to create a new drawing layer.

[FilipLeitner]

On current develop and without an error I was able to :

• create new drawing layer (saved to layman succesfully also)
• load already existing layer from layman
• edit loaded layer (add/delete polygon feature)

[fzadrazil]

It happens when you are not logged in, open draw panel, click on New drawing layer, Login from the dialog and try to create new layer. It crashes on this line as this.selectedLayer is null https://github.com/hslayers/hslayers-ng/blob/c91cae1e30ddd23c64dedef4645969a541f96380/projects/hslayers/src/components/draw/draw.service.ts#L410