Fix marker dragging disabling when marker is removed beforehand

[mlazowik]

Caused by Leaflet/Leaflet#5295

[mho22]

Same error caused by Leaflet/Leaflet#5295

When disabling the layer in Control.layer when Edition enabled, causes error due to code removeHooks in Leaflet.draw/Edit.Marker.js

// @method removeHooks(): void
	// Remove listener hooks from this handler
	removeHooks: function () {
		var marker = this._marker;

		marker.dragging.disable();
		marker.off('dragend', this._onDragEnd, marker);
		this._toggleMarkerHighlight();
	},

marker.dragging is inexistant here

[ same with AddHooks when Control Layer is disabled ]