Fixes the atrocinator modsuit module (#74529)

## About The Pull Request

Somewhere gravity got modified where you can have values below -1. This
updates all the checks for `NEGATIVE_GRAVITY` to reflect that.

Closes https://github.com/tgstation/tgstation/issues/72794
Closes https://github.com/Skyrat-SS13/Skyrat-tg/issues/20314

Confirmed https://github.com/tgstation/tgstation/issues/64703 is still
an issue. Fireman carrying prevents it from happening, Something to do
with buckle code probably, but I care not to investigate further at this
moment. Just stating in case anyone else does.

I did not experience the chat bug though. Don't think it's related. 

## Why It's Good For The Game


![dreamseeker_BiZRIyQ3Qe](https://user-images.githubusercontent.com/13398309/230061927-646223c4-861a-4dc9-89d9-495c123a016f.gif)

## Changelog

🆑
fix: the atrocinator modsuit mod will now make you fall up again when
activated.
/🆑

code/modules/mod/modules/modules_maint.dm

@@ -310,7 +310,7 @@
 /obj/item/mod/module/atrocinator/proc/check_upstairs()
 	SIGNAL_HANDLER
 
-	if(you_fucked_up || mod.wearer.has_gravity() != NEGATIVE_GRAVITY)
+	if(you_fucked_up || mod.wearer.has_gravity() > NEGATIVE_GRAVITY)
 		return
 	var/turf/open/current_turf = get_turf(mod.wearer)
 	var/turf/open/openspace/turf_above = get_step_multiz(mod.wearer, UP)