Use random port in registry IT

[ruanwenjun]

Purpose of the pull request

• Fix the UT will conflict with local port.
• The UT failed frequently, I am not sure if this is due to the port conflict.

Brief change log

Verify this pull request

This pull request is code cleanup without any test coverage.

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This pull request is already covered by existing tests, such as (please describe tests).

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This change added tests and can be verified as follows:

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If your pull request contain incompatible change, you should also add it to docs/docs/en/guide/upgrede/incompatible.md