Fix path case: legacy to Legacy.

Tools/DevLoader/BabylonLoader.js

@@ -192,7 +192,7 @@ var BABYLONDEVTOOLS;
 
         Loader.prototype.loadCoreDev = function() {
             // Es6 core import
-            this.loadESMScript(babylonJSPath + "/.temp/" + localDevES6FolderName + "/core/legacy/legacy.js");
+            this.loadESMScript(babylonJSPath + "/.temp/" + localDevES6FolderName + "/core/Legacy/legacy.js");
         }
 
         Loader.prototype.loadModule = function(moduleName, module) {
@@ -260,4 +260,4 @@ var BABYLONDEVTOOLS;
     var loader = new Loader();
     BABYLONDEVTOOLS.Loader = loader;
 
-})(BABYLONDEVTOOLS || (BABYLONDEVTOOLS = {}))
+})(BABYLONDEVTOOLS || (BABYLONDEVTOOLS = {}))