challenge: rename token4 to bonus2, to match subject

pkg/challenge/init

@@ -46,7 +46,7 @@ done
 # Launch some daemons
 #/usr/bin/setsid /usr/sbin/crond > /dev/null &
 
-# Prepare token 4
+# Prepare bonus 2
 mkdir -p /mnt
 
 for l in a b c d e f g h i j k l m n o p q r s t u v w x y z zz; do
@@ -64,9 +64,9 @@ N2=$((25 + $RANDOM % 35))
     echo -n $N2
     echo -n ${USER_PKEY:$N1:$N2} | sha512sum | cut -d " " -f 1
 
-} > /mnt/token4
+} > /mnt/bonus2
 sync
-rm /mnt/token4
+rm /mnt/bonus2
 sync
 umount /mnt