Fix the regex based on review comment.

Author: dangoor

src/preferences/PreferencesBase.js

@@ -176,7 +176,7 @@ define(function (require, exports, module) {
                     self._lineEndings = FileUtils.sniffLineEndings(text);
 
                     // If the file is empty, turn it into an empty object
-                    if (/^\w*$/.test(text)) {
+                    if (/^\s*$/.test(text)) {
                         result.resolve({});
                     } else {
                         try {

test/spec/PreferencesBase-test.js

@@ -1217,10 +1217,7 @@ define(function (require, exports, module) {
                 runs(function () {
                     promise.then(function (data) {
                         expect(data).toEqual({});
-                    })
-                        .fail(function (error) {
-                            expect("There should have been no error").toEqual("");
-                        });
+                    });
                 });
             });
         });