Corrected example for refreshIconOptions
Corrected example for refreshIconOptions

Corrected example for `L.Marker.refreshIconOptions` method.
Leaflet/Leaflet.markercluster,frenomus/Leaflet.markercluster,frenomus/Leaflet.markercluster,nerik/Leaflet.markercluster,ghybs/Leaflet.markercluster,Leaflet/Leaflet.markercluster,ghybs/Leaflet.markercluster,zverev/Leaflet.markercluster,604557209/byzgf,zverev/Leaflet.markercluster,nerik/Leaflet.markercluster,604557209/byzgf