[O] make org-agenda-tree-to-indirect-buffer use new frame only

[Viktor Rosenfeld]

Hi,

I've recently switched from Aquamacs to Emacs.app and noticed a
different behavior of C-c C-x b in the agenda. I have the following in
my Emacs settings:

(setq org-indirect-buffer-display 'new-frame)

If I open in indirect buffer from the agenda, it creates a new frame,
but also splits the agenda frame and opens the task in another window.
How can I stop it from doing the latter?

Thanks,
Viktor