Layer type GROUP not compatible with print-legend

[filleg]

Is your feature request related to a problem? Please describe.

When defining a layer as type GROUP you need to define a style for the group. Otherwise the inline legend returns "Teckenförklaring saknas". However when doing so the print won't work. Causing the print to crash and you need to reload the page entirely. If you omit a style for the grouplayer the print still crashes since it can't construct a request for the print-legend.

Describe the solution you'd like

Some kind of handling for grouplayers in the print-legend. Maybe using the layers in the group.

Describe alternatives you've considered

Open for suggestions.