Error {message: "Input data given to 'mapbox-gl-draw-cold' is not a valid GeoJSON object."} with DragCircleMode

[dvmai11]

This seems to be a known issue for DragCircleMode. (iamanvesh/mapbox-gl-draw-circle#21)
A potential fix for this - iamanvesh/mapbox-gl-draw-circle@71a3834

... geojson.properties.active = (isActivePolygon) ? Constants.activeStates.ACTIVE : Constants.activeStates.INACTIVE; if (state.polygon.properties.center.length > 0) return display(geojson);

[MaxHammermann]

As this problem is still present, can someone merge this?