Merge pull request #685 from nextcloud/dependabot/composer/guzzlehttp/guzzle-7.3.0

Bump guzzlehttp/guzzle from 7.2.0 to 7.3.0

Author: ChristophWurst

composer.lock

@@ -338,7 +338,7 @@ public function unregister()
      * Loads the given class or interface.
      *
      * @param  string    $class The name of the class
-     * @return bool|null True if loaded, null otherwise
+     * @return true|null True if loaded, null otherwise
      */
     public function loadClass($class)
     {
@@ -347,6 +347,8 @@ public function loadClass($class)
 
             return true;
         }
+
+        return null;
     }
 
     /**