event still called after control is removed from map

[puggimer]

When the layer is removed, it still has an event listener on the map (for 'zoomend' ). If this is triggered, it causes an exception because it is no attached to a map so values it depends on are null.

Simple fix - turn off the 'zoomend' event in the onRemove function (the onRemove should turn off all the events that onAdd turns on)

.off('zoomend', this._onZoomEnd, this)