improvements-to-message-queue-consumer-processes: Fixed resolving "sleep" value during executing Magento\Framework\MessageQueue\CallbackInvoker::invoke() method.

Author: Neos2007

lib/internal/Magento/Framework/MessageQueue/CallbackInvoker.php

@@ -70,7 +70,7 @@ public function invoke(
         $sleep = null
     ) {
         $this->poisonPillVersion = $this->poisonPillRead->getLatestVersion();
-        $sleep = (int) $sleep ?? 1;
+        $sleep = (int) $sleep ?: 1;
         $maxIdleTime = $maxIdleTime ? (int) $maxIdleTime : PHP_INT_MAX;
         for ($i = $maxNumberOfMessages; $i > 0; $i--) {
             $idleStartTime = microtime(true);