Fix emphasis infotext missing from params.txt

[catboxanon]

Description

Fixes a logic order where the prompt emphasis is determined after params.txt has already been written, meaning it would be missing from the infotext (if applicable). Discovered this while implementing #15141.

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests