Fixes the screens of unpowered PDAs disappearing (#22962)

As the title says, it has bothered me for a bit. Now every PDA base
sprite has a screen instead of relying on the overlays to add one on
them.
This _somewhat_ unfortunately resulted in the PDAs which had any alpha
(transparency) on their screens to no longer have them. No big loss.

From the changelog:
>  - bugfix: "The screens of unpowered PDAs no longer disappear"

Most likely should have done it it properly with overlays, but this also
works.

code/modules/modular_computers/computers/subtypes/dev_pda.dm

@@ -17,6 +17,12 @@
 	icon_state_unpowered = icon_state
 	icon_state_broken = icon_state
 
+/obj/item/modular_computer/handheld/pda/update_icon()
+	. = ..()
+	if(!enabled)
+		AddOverlays("off")
+		return
+
 /obj/item/modular_computer/handheld/pda/old
 	icon = 'icons/obj/modular_computers/pda_old.dmi'
 

code/modules/modular_computers/computers/subtypes/dev_wristbound.dm

@@ -18,6 +18,12 @@
 	icon_state_unpowered = icon_state
 	icon_state_broken = icon_state
 
+/obj/item/modular_computer/handheld/wristbound/update_icon()
+	. = ..()
+	if(!enabled)
+		AddOverlays("off")
+		return
+
 /obj/item/modular_computer/handheld/wristbound/attack_hand(mob/user)
 	if(ishuman(user))
 		var/mob/living/carbon/human/H = user

html/changelogs/ElorgRHG-unpowered-pda-fix.yml

@@ -0,0 +1,13 @@
+# Your name.
+author: ElorgRHG
+
+# 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, this gets changed to [] after reading.  Just remove the brackets when you add new shit.
+# Please surround your changes in  double quotes ("). It works without them, but if you use certain characters it screws up compiling. The quotes will not show up in the changelog.
+changes:
+  - bugfix: "The screens of unpowered PDAs no longer disappear"