fixed failure deploy contract with an existed account

[AionJayT]

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Description

Please include a brief summary of the change that this pull request proposes. Include any relevant motivation and context. List any dependencies required for this change.

• The current kernel can't deploy a new contract to an existing account (this account might be funded by another account). Therefore, the fix allows the contract deployer deploy a new contract to an existing account without code in the database, which means the destination account only has some balance.

Fixes Issue # .

Type of change

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• Bug fix.
• New feature.
• Enhancement.
• Unit test.
• Breaking change (a fix or feature that causes existing functionality to not work as expected).
• Requires documentation update.

Testing

Please describe the tests you used to validate this pull request. Provide any relevant details for test configurations as well as any instructions to reproduce these results.

• added test cases in the contractIntegTest.

Verification

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• I have self-reviewed my own code and conformed to the style guidelines of this project.
• New and existing tests pass locally with my changes.
• I have added tests for my fix or feature.
• I have made appropriate changes to the corresponding documentation.
• My code generates no new warnings.
• Any dependent changes have been made.