Update torrc.sample.in to IPv6Exit 1 being an exit by default

src/config/torrc.sample.in

@@ -174,13 +174,11 @@
 
 ## Uncomment this if you want your relay to be an exit, with the default
 ## exit policy (or whatever exit policy you set below).
-## (If ReducedExitPolicy or ExitPolicy are set, relays are exits.
+## (If ReducedExitPolicy, ExitPolicy, or IPv6Exit are set, relays are exits.
 ## If neither exit policy option is set, relays are non-exits.)
 #ExitRelay 1
 
 ## Uncomment this if you want your relay to allow IPv6 exit traffic.
-## You must also set ExitRelay, ReducedExitPolicy, or ExitPolicy to make your
-## relay into an exit.
 ## (Relays do not allow any exit traffic by default.)
 #IPv6Exit 1