[hotfix] Fix incorrect messageKey passed in ScalingLimited event

Author: huyuanfeng

flink-autoscaler/src/main/java/org/apache/flink/autoscaler/JobVertexScaler.java

@@ -456,7 +456,7 @@ protected static <KEY, Context extends JobAutoScalerContext<KEY>> int scale(
                 AutoScalerEventHandler.Type.Warning,
                 SCALING_LIMITED,
                 message,
-                SCALING_LIMITED + vertex + (scaleFactor * currentParallelism),
+                SCALING_LIMITED + vertex + newParallelism,
                 context.getConfiguration().get(SCALING_EVENT_INTERVAL));
         return p;
     }