Remove unused parameters

src/freedombone-image-customise

@@ -427,11 +427,6 @@ WIFI_CHANNEL=2
 BATMAN_CELLID='02:BA:00:00:03:01'
 WIFI_SSID='mesh'
 
-rootdir=''
-FN=
-CHROOT_PREFIX=chroot "$rootdir"
-FRIENDS_MIRRORS_SERVER=
-
 # To avoid confusions these are obtained from the main project file
 TOXID_REPO=
 TOX_PORT=