Update test to consume less memory

Author: arnaud-lb

Zend/tests/stack_limit/stack_limit_011.phpt

@@ -19,11 +19,15 @@ function replace2() {
     }, 'x');
 }
 function replace() {
-    return preg_replace_callback('#.#', function () {
+    static $once = false;
+    return preg_replace_callback('#.#', function () use (&$once) {
         try {
             replace();
         } finally {
-            replace2();
+            if (!$once) {
+                $once = true;
+                replace2();
+            }
         }
     }, 'x');
 }