Fixes #1421, #1412 + runtimes (#1422)

Fixes #1421
Fixes runtime spam from Pun Pun
Fixes runtimes from NTIRC
Fixes #1412

code/game/objects/items/weapons/storage/backpack.dm

@@ -22,7 +22,7 @@
 		)
 	w_class = 4
 	slot_flags = SLOT_BACK
-	max_w_class = 4
+	max_w_class = 3
 	max_storage_space = 28
 	var/species_restricted = list("exclude","Vaurca Breeder")
 

code/modules/mob/living/carbon/human/life.dm

@@ -1603,7 +1603,8 @@
 		if (regen > 0)
 			stamina = min(max_stamina, stamina+regen)
 			nutrition = max(0, nutrition - stamina_recovery*0.18)
-			hud_used.move_intent.update_move_icon(src)
+			if (client)
+				hud_used.move_intent.update_move_icon(src)
 
 /mob/living/carbon/human/proc/update_health_display()
 	if(!healths)

code/modules/mob/living/life.dm

@@ -110,7 +110,7 @@
 
 /mob/living/proc/handle_disabilities()
 	//Eyes
-	if(disabilities & BLIND || stat)	//blindness from disability or unconsciousness doesn't get better on its own
+	if(sdisabilities & BLIND || stat)	//blindness from disability or unconsciousness doesn't get better on its own
 		eye_blind = max(eye_blind, 1)
 	else if(eye_blind)			//blindness, heals slowly over time
 		eye_blind = max(eye_blind-1,0)
@@ -118,7 +118,7 @@
 		eye_blurry = max(eye_blurry-1, 0)
 
 	//Ears
-	if(disabilities & DEAF)		//disabled-deaf, doesn't get better on its own
+	if(sdisabilities & DEAF)		//disabled-deaf, doesn't get better on its own
 		setEarDamage(-1, max(ear_deaf, 1))
 	else
 		// deafness heals slowly over time, unless ear_damage is over 100

code/modules/modular_computers/NTNet/NTNRC/conversation.dm

@@ -29,7 +29,7 @@ var/global/ntnrc_uid = 0
 		return
 	for(var/message in messages)
 		messages -= message
-		if(messages <= 50)
+		if(messages.len <= 50)
 			return
 
 /datum/ntnet_conversation/proc/add_client(var/datum/computer_file/program/chatclient/C)
@@ -65,4 +65,4 @@ var/global/ntnrc_uid = 0
 		return 0 // Not Authorised
 
 	add_status_message("[client.username] has changed channel title from [title] to [newtitle]")
-	title = newtitle
+	title = newtitle