fix: nil pushHandler crash in message Create

internal/message/handlers.go

@@ -34,6 +34,8 @@ func NewHandler(db *sql.DB, hub *gateway.Hub, pushHandler *push.Handler, logger
 		db:          db,
 		hub:         hub,
 		mentions:    NewMentionHandler(db, pushHandler, logger),
+		pushHandler: pushHandler,
+		logger:      logger,
 	}
 }