[ticket/12009] Move valid extensions in tests to correct dir structure.

PHPBB3-12009

tests/extension/ext/vendor2/foo/ext.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace vendor2\foo;
+
+class ext extends \phpbb\extension\base
+{
+	static public $disabled;
+
+	public function disable_step($old_state)
+	{
+		self::$disabled = true;
+
+		return false;
+	}
+}