Fixes gun misfires always happening (shiptest-ss13#3363)

<!-- Write **BELOW** The Headers and **ABOVE** The comments else it may
not be viewable. -->
<!-- You can view Contributing.MD for a detailed description of the pull
request process. -->

## About The Pull Request

<!-- Describe The Pull Request. Please be sure every change is
documented or this can delay review and even discourage maintainers from
merging your PR! -->

I fucked up, sorrrrryyy. I forgot to fix the chances

## Why It's Good For The Game

<!-- Please add a short description of why you think these changes would
benefit the game. If you can't justify it in words, it might not be
worth adding. -->

Fixes good

## Changelog

:cl:
fix: Misfires no longer have 100% chance
/:cl:

<!-- Both :cl:'s are required for the changelog to work! You can put
your name to the right of the first :cl: if you want to overwrite your
GitHub username as author ingame. -->
<!-- You can use multiple of the same prefix (they're only used for the
icon ingame) and delete the unneeded ones. Despite some of the tags,
changelogs should generally represent how a player might be affected by
the changes rather than a summary of the PR's contents. -->

code/__DEFINES/guns.dm

@@ -70,9 +70,9 @@
 #define MANUFACTURER_IMPORT "Lanchester Import Co."
 
 // Misfire chances if the gun's safety is off
-#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_LOW 100
-#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_MEDIUM 100
-#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_HIGH 100
+#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_LOW 5
+#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_MEDIUM 10
+#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_HIGH 15
 
 /////////////////
 // ATTACHMENTS //