Remove incorrect HistoryNavigator test case -

Doesn't test what it describes. 'adding an existing item changes the order' covers this. See https://github.com/Microsoft/vscode/commit/c84be6409a0e515f19ce71ff2c0582b5cec9732d

src/vs/base/test/common/history.test.ts

@@ -82,14 +82,6 @@ suite('History Navigator', () => {
 		assert.deepEqual(['4', '5'], toArray(testObject));
 	});
 
-	test('adding existing element changes the position', function () {
-		let testObject = new HistoryNavigator(['1', '2', '3', '4'], 2);
-
-		testObject.add('2');
-
-		assert.deepEqual(['4', '2'], toArray(testObject));
-	});
-
 	test('add resets the navigator to last', function () {
 		let testObject = new HistoryNavigator(['1', '2', '3', '4'], 3);