[sync] authorization problem with P1i

[Mario Liehr]

> It still doesn't make sense. If you call the same method with the same
> parameters, and this message does successful authentication anywhere
> else in Horde, and it should work here too.
This hint showed me somehow the way. It was
$conf['auth']['driver']='composite'. I changed it to application - imp
and now it works. Somehow strange anyway, possibly a bug?

Is there a need to find the real error? Of course I will try to do this,
but probably I need some help.

best regards
Mario