bug#31650: 26.1; Desktop mode adds wm stickiness to emacs windows.

[Rolf Ade]

I've

(desktop-save-mode 1)

in my init.el. This works fine for rare occasions is restart emacs.
Though, after restart, I not only find all my files open but the eamcs
window "sticky" speaking in windows manager terms, meaning if I jump to
another virtual desktop, my emacs windwos will "follow" me.

The emacs window wasn't in this state at the last
save-buffers-kill-terminal call. It doesn't have this state if I start
emacs -Q. It's  desktop-save-mode, that put my emacs window into this
state.

It's a minor nuisance, no doubt, but it's clearly wrong.

I'm using GNU Emacs 26.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 2.24.10) of 2018-05-29 built on linux-qg7d Repository revision:
 07f8f9bc5a51f5aa94eb099f3e15fbe0c20ea1ea Windowing system distributor
 'The X.Org Foundation', version 11.0.11203000 (x86_64) and as windows
 manager fvwm 2.6.