[zendframework/zendframework#1200] Fix paginator cache usage

- Due to zendframework/zendframework#1200, had to change how Paginator tests for a cache hit

src/Paginator.php

@@ -695,7 +695,7 @@ public function getItemsByPage($pageNumber)
 
         if ($this->_cacheEnabled()) {
             $data = self::$_cache->getItem($this->_getCacheId($pageNumber));
-            if ($data !== false) {
+            if ($data) {
                 return $data;
             }
         }