Fix genWillData missing properties

Author: sy-records

src/Handler/AbstractHandler.php

@@ -190,6 +190,7 @@ public function genWillData(): array
                 'message' => $this->getWillMessage(),
                 'qos' => $this->getWillQos(),
                 'retain' => $this->getWillRetain(),
+                'properties' => $this->getProperties('will'),
             ];
         }