Fixed webgl_materials_blending_custom. Fixes #7521.

examples/webgl_materials_blending_custom.html

@@ -189,13 +189,11 @@
 				for ( var i = 0; i < images.length; i ++ ) {
 
 					var map = THREE.ImageUtils.loadTexture( images[ i ] );
+					mapsNoPre.push( map );
 
-					var mapPre = map.clone();
-
+					var mapPre = THREE.ImageUtils.loadTexture( images[ i ] );
 					mapPre.premultiplyAlpha = true;
 					mapPre.needsUpdate = true;
-
-					mapsNoPre.push( map );
 					mapsPre.push( mapPre );
 
 				}