Fix function name

Author: ben-lu-uw

src/mapml-viewer.js

@@ -219,7 +219,7 @@ export class MapViewer extends HTMLElement {
 
           this.setControls(false,false,true);
           this._crosshair = M.crosshair().addTo(this._map);
-          this._featureIndexBox = M.featureIndex().addTo(this._map);
+          this._featureIndex = M.featureIndex().addTo(this._map);
           // https://github.com/Maps4HTML/Web-Map-Custom-Element/issues/274
           this.setAttribute('role', 'application');
           // Make the Leaflet container element programmatically identifiable

src/web-map.js

@@ -233,7 +233,7 @@ export class WebMap extends HTMLMapElement {
 
           this.setControls(false,false,true);
           this._crosshair = M.crosshair().addTo(this._map);
-          this._featureIndexBox = M.featureIndexBox().addTo(this._map);
+          this._featureIndex = M.featureIndex().addTo(this._map);
 
           if (this.hasAttribute('name')) {
             var name = this.getAttribute('name');