Pressure floor accidentally removed in refactor #577
Description
The pressure floor that was present in the initial version of the spam pressure system (which made sure that pressure for a user was never below 0) was accidentally removed in a refactor of the spam pressure system. While this is believed to be a minor issue, this is unintended behaviour which I intend to fix.
As this code change is a single (or a few) lines of code, i feel like this qualifies as a good first issue for anyone wanting to pick this up other than me. Just comment here that you would like to take a go at fixing this and it'll be assigned to you.