[dev] Bug in setlayout()

Hi,

I've just notice the layout symbol is not updated unless there is a
client in the current view.

To reproduce it you can follow these steps:
- Switch to an empty view.
- Mod+{t,f,m}. The layout symbol doesn't change.
- Switch to a view with a client. Then the layout symbol is updated.

I don't know if it's the expected behavior. If it isn't I attach a
patch with a possible solution.

Kind regards,
Nibble