Updated mysql2 to version 3.9.7 for security updates

[jebarpg]

Checklist

• [x] run npm run test and npm run benchmark
• [x] tests and/or benchmarks are included
• [x] documentation is changed or added
• [x] commit message and code follows the Developer's Certification of Origin and the Code of conduct

Ran all the test and they all 5 suites and all 131 tests pass 100%. This fixes the issue with Snyk in issue #138