Fix versioned _createTile
Fix versioned _createTile

Previously, even if leaflet version was > 7, it was still using _oldCreateTile, which is incorrect.
domoritz/leaflet-maskcanvas,Carlowahlen/leaflet-maskcanvas,minhpl/leaflet-maskcanvas_needfix,Carlowahlen/leaflet-maskcanvas,minhpl/leaflet-maskcanvas_needfix