default timeout to zero instead of null to fix deprecated error in PH…

…P 8.1

src/Bridge/GearmanPeclManager.php

@@ -50,7 +50,7 @@ protected function start_lib_worker($worker_list, $timeouts = array()) {
         }
 
         foreach ($worker_list as $w) {
-            $timeout = (isset($timeouts[$w]) ? $timeouts[$w] : null);
+            $timeout = (isset($timeouts[$w]) ? $timeouts[$w] : 0);
             $this->log("Adding job $w ; timeout: " . $timeout, GearmanManager::LOG_LEVEL_WORKER_INFO);
             $thisWorker->addFunction($w, array($this, "do_job"), $this, $timeout);
         }