Fix failing tests with CakeRequest when ran in webrunner

lib/Cake/Test/Case/Network/CakeRequestTest.php

@@ -1139,6 +1139,7 @@ class CakeRequestTest extends CakeTestCase {
  * @return void
  */
 	public function testGetParamsWithDot() {
+		$_GET = array();
 		$_GET['/posts/index/add_add'] = '';
 		$_SERVER['PHP_SELF'] = '/cake_dev/app/webroot/index.php';
 		$_SERVER['REQUEST_URI'] = '/cake_dev/posts/index/add.add';
@@ -1153,6 +1154,7 @@ class CakeRequestTest extends CakeTestCase {
  * @return void
  */
 	public function testGetParamWithUrlencodedElement() {
+		$_GET = array();
 		$_GET['/posts/add/∂∂'] = '';
 		$_SERVER['PHP_SELF'] = '/cake_dev/app/webroot/index.php';
 		$_SERVER['REQUEST_URI'] = '/cake_dev/posts/add/%E2%88%82%E2%88%82';