remove duplicate _arraySplice
remove duplicate _arraySplice

Leaflet/Leaflet.markercluster,frenomus/Leaflet.markercluster,ghybs/Leaflet.markercluster,604557209/byzgf,nerik/Leaflet.markercluster,nerik/Leaflet.markercluster,Leaflet/Leaflet.markercluster,zverev/Leaflet.markercluster,604557209/byzgf,ghybs/Leaflet.markercluster,frenomus/Leaflet.markercluster,zverev/Leaflet.markercluster