Revert "Clean up."

This reverts commit be60454c5fe65cb625ae9df6a93ad7284cff31aa.

examples/jsm/exporters/GLTFExporter.js

@@ -1299,7 +1299,6 @@ class GLTFWriter {
 		// pbrMetallicRoughness.metallicRoughnessTexture
 		const metalnessMap = material.metalnessMap?.image ? material.metalnessMap : undefined;
 		const roughnessMap = material.roughnessMap?.image ? material.roughnessMap : undefined;
-
 		if ( metalnessMap || roughnessMap ) {
 
 			const metalRoughTexture = this.buildMetalRoughTexture( metalnessMap, roughnessMap );