fix(microservice): Fix KafkaServer constructor

[smhmayboudi]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[X] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: #5599

What is the new behavior?

You can overwrite the KafkaServer constructor without a typescript error.

Does this PR introduce a breaking change?

[ ] Yes
[X] No

Other information

[coveralls]

Pull Request Test Coverage Report for Build 31528

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• 159 unchanged lines in 31 files lost coverage.
• Overall coverage increased (+0.6%) to 95.443%

---

Files with Coverage Reduction	New Missed Lines	%
packages/common/decorators/http/route-params.decorator.ts	1	88.1%
packages/common/pipes/validation.pipe.ts	1	94.38%
packages/core/router/router-execution-context.ts	1	97.42%
packages/microservices/client/client-redis.ts	1	92.86%
packages/microservices/server/server-kafka.ts	1	97.54%
packages/microservices/server/server-mqtt.ts	1	96.83%
packages/websockets/socket-server-provider.ts	1	91.18%
packages/common/decorators/core/apply-decorators.ts	2	66.67%
packages/common/decorators/core/set-metadata.decorator.ts	2	85.71%
packages/microservices/client/client-kafka.ts	2	97.12%

Totals
Change from base Build cf4f5692-9ee1-4371-8130-5c6f9c02faac:	0.6%
Covered Lines:	4482
Relevant Lines:	4696

---

💛 - Coveralls