Tweak blood deficiency to be less deadly by itself (#43501)

I came to the conclusion that quirks that put you on a death timer are
dumb and boring, one such reason being they make you unable to go AFK for
any length of time but also aren't interesting to manage other than
lugging around whatever medicine you need to survive every round.

Blood loss now stops just above a survivable threshold, meaning when left
untreated even the smallest of wounds is potentially lethal, hence it's
still 2 points. Watch out for paper cuts.

Renamed just to make it a bit shorter and less spooky.

code/datums/traits/negative.dm

@@ -16,7 +16,7 @@
 		SEND_SIGNAL(quirk_holder, COMSIG_CLEAR_MOOD_EVENT, "back_pain")
 
 /datum/quirk/blooddeficiency
-	name = "Acute Blood Deficiency"
+	name = "Blood Deficiency"
 	desc = "Your body can't produce enough blood to sustain itself."
 	value = -2
 	gain_text = "<span class='danger'>You feel your vigor slowly fading away.</span>"
@@ -28,7 +28,8 @@
 	if(NOBLOOD in H.dna.species.species_traits) //can't lose blood if your species doesn't have any
 		return
 	else
-		quirk_holder.blood_volume -= 0.275
+		if (H.blood_volume > (BLOOD_VOLUME_SAFE - 25)) // just barely survivable without treatment
+			H.blood_volume -= 0.275
 
 /datum/quirk/blindness
 	name = "Blind"