fixed test for php5.3

Author: oscarotero

tests/files/phpcode.php

@@ -16,7 +16,7 @@
     <p><?php __("text 7 (with parenthesis)"); ?></p>
     <p><?php __("text 8 \"with escaped double quotes\""); ?></p>
     <p><?php __("text 9 'with single quotes'"); ?></p>
-    <p><?= n__("text 10 with plural", "The plural form", 5); ?></p>
+    <p><?php echo n__("text 10 with plural", "The plural form", 5); ?></p>
 </div>
 
 <?php __e("<div id=\"blog\" class=\"container\">