You can no longer RNG head KO anyone with a helmet (#7342)

What happens: You have a melee weapon. You hit someone with it while aiming for the head. There's always a chance to make them go to sleep for a ridicolous length - like 45 seconds.

But they have a helmet on! This is a pretty lame mechanic in that case.

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

@@ -276,7 +276,7 @@ emp_act
 		if(!stat)
 			if(headcheck(hit_zone))
 				//Harder to score a stun but if you do it lasts a bit longer
-				if(prob(effective_force))
+				if(prob(effective_force) && head && !istype(head, /obj/item/clothing/head/helmet))
 					visible_message("<span class='danger'>[src] [species.knockout_message]</span>")
 					apply_effect(20, PARALYZE, blocked)
 			else

html/changelogs/mattatlas-noheadkos.yml

@@ -0,0 +1,41 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes: 
+#   bugfix
+#   wip (For works in progress)
+#   tweak
+#   soundadd
+#   sounddel
+#   rscadd (general adding of nice things)
+#   rscdel (general deleting of nice things)
+#   imageadd
+#   imagedel
+#   maptweak
+#   spellcheck (typo fixes)
+#   experiment
+#   balance
+#   admin
+#   backend
+#   security
+#   refactor
+#################################
+
+# Your name.  
+author: MattAtlas
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, all entries are changed into a single [] after a master changelog generation. Just remove the brackets when you add new entries.
+# Please surround your changes in  double quotes ("), as certain characters otherwise screws up compiling. The quotes will not show up in the changelog.
+changes: 
+  - rscdel: "You can no longer knock someone out with a melee weapon while aiming for the head if they have a helmet on."