Changes nutrition with blood loss (#4231)

# About the pull request

Nutrition now slowly lowers when you are regaining blood rather than
losing it rapidly when you have lower effective blood.

# Explain why it's good for the game

The other way was dumb. This way may be less dumb.


# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog

:cl: Morrow
balance: You now lose nutrition when gaining blood rather than losing a
ton of nutrition when you have low effective blood
/:cl:

code/modules/mob/living/blood.dm

@@ -12,8 +12,9 @@
 
 	if(stat != DEAD && bodytemperature >= 170) //Dead or cryosleep people do not pump the blood.
 		//Blood regeneration if there is some space
-		if(blood_volume < max_blood)
+		if(blood_volume < max_blood && nutrition >= 1)
 			blood_volume += 0.1 // regenerate blood VERY slowly
+			nutrition -= 0.25
 		else if(blood_volume > max_blood)
 			blood_volume -= 0.1 // The reverse in case we've gotten too much blood in our body
 			if(blood_volume > limit_blood)
@@ -43,12 +44,6 @@
 			if(oxyloss < maximum_oxyloss)
 				oxyloss += round(max(additional_oxyloss, 0))
 
-			//Bloodloss effects on nutrition
-			if(nutrition >= 300)
-				nutrition -= 10
-			else if(nutrition >= 200)
-				nutrition -= 3
-
 		switch(b_volume)
 			if(BLOOD_VOLUME_OKAY to BLOOD_VOLUME_SAFE)
 				if(prob(1))