Mindbreaker Tweak (#3052)

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## About The Pull Request
A small followup to #3017,
this considerably slows the metabolism on chemical mindbreaker.
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## Why It's Good For The Game

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With the old implementation, chemical mindbreaker could hardly be used
to treat RDS. A 50u dose would last only a few minutes, and destroy your
liver in the process. This makes RDS actually viable to treat.

Also, if you're taking chemical mindbreaker recreationally, you naughty
dog you, this allows you the chance to hallucinate for more than a brief
moment, given how hallucinations are weighted. Not a very useful
recreational substance if it exits your system within thirty seconds.
## Changelog

:cl:
balance: chemical mindbreaker is now ten times as potent! Be gay, do
crime, and hallucinate in the process
/:cl:

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code/modules/reagents/chemistry/reagents/toxin_reagents.dm

@@ -255,6 +255,7 @@
 	name = "Mindbreaker Toxin"
 	description = "A powerful hallucinogen. Not a thing to be messed with. For some mental patients. it counteracts their symptoms and anchors them to reality."
 	color = "#B31008" // rgb: 139, 166, 233
+	metabolization_rate = 0.1 * REAGENTS_METABOLISM
 	toxpwr = 0
 	taste_description = "sourness"