Single tileUrlFunction in createFromTileUrlFunctions

In that case, simply return the single tileUrlFunction.

src/ol/source/wmtssource.js

@@ -113,8 +113,6 @@ ol.source.WMTS = function(wmtsOptions) {
     };
   }
 
-  // TODO: update createFromTileUrlFunctions so that if
-  // tileUrlFunctions.length == 1, it returns the only tileUrlFunction
   var tileUrlFunction = ol.TileUrlFunction.createFromTileUrlFunctions(
       goog.array.map(urls, function(url) {
         if (goog.isDef(kvpParams)) {

src/ol/tileurlfunction.js

@@ -60,6 +60,9 @@ ol.TileUrlFunction.createFromTemplates = function(templates) {
  * @return {ol.TileUrlFunctionType} Tile URL function.
  */
 ol.TileUrlFunction.createFromTileUrlFunctions = function(tileUrlFunctions) {
+  if (tileUrlFunctions.length === 1) {
+    return tileUrlFunctions[0];
+  }
   return function(tileCoord, tileGrid, projection) {
     if (goog.isNull(tileCoord)) {
       return undefined;