fixed error from using a grab on a disposal chute

Signed-off-by: CaelAislinn <cael_aislinn@yahoo.com.au>

code/modules/recycling/disposal.dm

@@ -44,6 +44,10 @@
 		if(stat & BROKEN)
 			return
 
+		//robots shouldn't be able to grab/carry stuff anyway
+		if(isrobot(user))
+			return
+
 		if(istype(I, /obj/item/weapon/melee/energy/blade))
 			user << "You can't place that item inside the disposal unit."
 			return
@@ -91,10 +95,6 @@
 					for (var/mob/C in viewers(src))
 						C.show_message("\red [GM.name] has been placed in the [src] by [user].", 3)
 					del(G)
-
-		if(isrobot(user))
-			return
-
 		else
 			if(!I || isnull(I))
 				//CRASH("disposal/attackby() was called, but I was nulled before calling user.drop_item()")