fix migrationRule bug

[xiaoheng1]

What is the purpose of the change

fix migrationRule bug

Brief changelog

Verifying this change

Checklist

• Make sure there is a GitHub_issue field for the change (usually before you start working on it). Trivial changes like typos do not require a GitHub issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
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• Check if is necessary to patch to Dubbo 3 if you are work on Dubbo 2.7
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Add some description to dubbo-website project if you are requesting to add a feature.
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[codecov-commenter]

Codecov Report

Merging #8358 (d27593a) into master (d82ce47) will decrease coverage by 0.26%.
The diff coverage is 7.69%.

@@             Coverage Diff              @@
##             master    #8358      +/-   ##
============================================
- Coverage     61.28%   61.01%   -0.27%     
+ Complexity      447      445       -2     
============================================
  Files          1096     1096              
  Lines         44212    44177      -35     
  Branches       6445     6414      -31     
============================================
- Hits          27094    26955     -139     
- Misses        14135    14237     +102     
- Partials       2983     2985       +2     

Impacted Files	Coverage Δ
...o/rpc/cluster/support/migration/MigrationRule.java	44.73% <7.69%> (-12.41%)	⬇️
...ng/transport/dispatcher/all/AllChannelHandler.java	62.06% <0.00%> (-34.49%)	⬇️
...rg/apache/dubbo/remoting/utils/PayloadDropper.java	76.92% <0.00%> (-15.39%)	⬇️
...ng/transport/dispatcher/WrappedChannelHandler.java	47.82% <0.00%> (-15.22%)	⬇️
...dubbo/common/status/support/LoadStatusChecker.java	50.00% <0.00%> (-11.54%)	⬇️
...che/dubbo/remoting/transport/mina/MinaChannel.java	35.52% <0.00%> (-10.53%)	⬇️
...dubbo/remoting/exchange/support/DefaultFuture.java	76.99% <0.00%> (-10.19%)	⬇️
.../remoting/transport/netty4/NettyClientHandler.java	76.27% <0.00%> (-10.17%)	⬇️
.../dubbo/remoting/transport/netty4/NettyChannel.java	54.45% <0.00%> (-9.91%)	⬇️
...mmon/threadpool/support/fixed/FixedThreadPool.java	80.00% <0.00%> (-7.50%)	⬇️
... and 38 more

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[chickenlj]

LGTM