fix lgtm issues

src/base/I3DMLoaderBase.js

@@ -15,7 +15,7 @@ export class I3DMLoaderBase {
 
 	resolveExternalURL( url ) {
 
-		if ( /^[^\\/]/ ) {
+		if ( /^[^\\/]/.test( url ) ) {
 
 			return this.workingPath + '/' + url;
 

src/three/DebugTilesRenderer.js

@@ -1,4 +1,4 @@
-import { Box3Helper, Group, MeshStandardMaterial, PointsMaterial, Color } from 'three';
+import { Box3Helper, Group, MeshStandardMaterial, PointsMaterial } from 'three';
 import { getIndexedRandomColor } from './utilities.js';
 import { TilesRenderer } from './TilesRenderer.js';
 import { SphereHelper } from './SphereHelper.js';