Fix potential NPE in Hessian2FactoryManager

[AlbumenJ]

What is the purpose of the change

Related with #13504

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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• 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.
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[sonarcloud]

Quality Gate passed

The SonarCloud Quality Gate passed, but some issues were introduced.

1 New issue
0 Security Hotspots
80.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud