Adds correct sprite sheets to ERT suits

Currently, only drask do have ERT hardsuit sprites, so it will only use
their sprites, else use the default sprite, instead of failing to find
sprites, and give invisible hardsuits.

code/modules/clothing/spacesuits/ert.dm

@@ -41,6 +41,10 @@
 	/obj/item/device/radio, /obj/item/device/analyzer, /obj/item/weapon/gun/energy/laser, /obj/item/weapon/gun/energy/pulse, \
 	/obj/item/weapon/gun/energy/gun/advtaser, /obj/item/weapon/melee/baton, /obj/item/weapon/gun/energy/gun)
 	strip_delay = 130
+	species_fit = list("Drask")
+	sprite_sheets = list(
+		"Drask" = 'icons/mob/species/drask/suit.dmi'
+		)
 
 //Commander
 /obj/item/clothing/head/helmet/space/hardsuit/ert/commander