[imp] Hook for from_addr works only when locked is set to false

[Yves Bilgeri]

Hello Horde Users!

I made a hook for the $_prefs['from_addr'] setting, set 'hook' => true 
and 'locked' => true. So this way the hook gets called and returns the 
right result, but now new entry in horde_prefs appear.

Now when I set 'locked' => false in $_prefs['from_addr'] it works, it 
sets the entry in horde_prefs. But I don't want that the user can change 
the from_addr and that's why I want to use the hook.

Why doesn't it work with 'locked' set to true?

Maybe I'm getting something wrong!

Thanks for any hint, Yves