Fix: Try to close mysql connection properly

[chakflying]

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Description

Fixes #3020

Searched around and there seems to be no way to determine the state of the connection without sending something, so this should be a good enough solution.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• My code follows the style guidelines of this project
• I ran ESLint and other linters for modified files
• I have performed a self-review of my own code and tested it
• I have commented my code, particularly in hard-to-understand areas
  (including JSDoc for methods)
• My changes generate no new warnings
• My code needed automated testing. I have added them (this is optional task)

Screenshots (if any)

[Zaid-maker]

Looks Good!

[louislam]

It is quite surprising that many database libraries in Node.js do not handle connection state gracefully. Perhaps they are designed for long-running applications.

[lenisko]

thanks!