Spiderfy the cluster only on max zoom

[Panic7]

Leaflet.markercluster/src/MarkerClusterGroup.js

Lines 868 to 874 in e5124b2

	if (bottomCluster._zoom === this._maxZoom &&
	bottomCluster._childCount === cluster._childCount &&
	this.options.spiderfyOnMaxZoom) {
	// All child markers are contained in a single cluster from this._maxZoom to this cluster.
	cluster.spiderfy();
	} else if (this.options.zoomToBoundsOnClick) {

I don't want to search for hacky ways to bypass this, in case I need to spiderfy the cluster only at the maximum zoom level. It would be nice to have a parameter for the cluster groups, like 'spyderfyOnMaxZoomOnly' or something