byobu-ctrl-a sets prefix2 to ctrl-a key

After tmux 1.6, byoub-ctrl-a command sets prefix2 to ctrl-a on screen mode.

How to reproduce:

1. Exec "byobu-ctrl-a"
2. Select "screen" mode
3. Press F12 and c keys

Expected behaviour:

* Create new window (as same as ctrl-a)

Actual behaviour:

* No effects.

I think that F12 key should be prefix key both mode "byobu-ctrl-a" modes.
According following code, from tmux 1.6, it seems that change that behaviour.

http://bazaar.launchpad.net/~kirkland/byobu/trunk/view/head:/usr/bin/byobu-ctrl-a.in#L124

---
$BYOBU_SED_INLINE -e "/^set -g prefix/d" -e "/ send-prefix/d" -e "/^unbind-key -n C-${key}/d" "$keybindings"
echo "unbind-key -n C-${key}" >> "$keybindings"
if $BYOBU_BACKEND -V | grep " 1.5"; then
 # tmux 1.5 supports a list of prefixes
 echo "set -g prefix ^${KEY},F12" >> "$keybindings"
else
 # tmux 1.6 and above supports prefix and prefix2
 echo "set -g prefix ^${KEY}" >> "$keybindings"
 echo "set -g prefix2 ^${KEY}" >> "$keybindings"
fi
---

How about following code?

---
 echo "set -g prefix2 F12" >> "$keybindings"
---