computer3 remote view exploit fix

you could look at any atom for a tick.
could need improvement, does not check camera network at the moment,
because of the costly and temporary nature of the getter proc.

code/WorkInProgress/computer3/computers/camera.dm

@@ -258,10 +258,11 @@
 
 		if("show" in href_list)
 			var/obj/machinery/camera/C = locate(href_list["show"])
-			current = C
-			usr.reset_view(C)
-			interact()
-			return
+			if(istype(C) && C.status)
+				current = C
+				usr.reset_view(C)
+				interact()
+				return
 
 		if("keyselect" in href_list)
 			current = null