Fix: Add missing FK for monitor-tls-info table

[chakflying]

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Description

The monitor-tls-info table has missing foreign key referencing the monitor table. This leads to orphan tls-info entries when monitors are deleted, which may take up disk space. Adding back the foreign key by modifying the table schema fixes this.

This fix is for 2.0. I think existing mariadb databases will not be affected.

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 generates no new warnings
• My code needed automated testing. I have added them (this is optional task)

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