Maximized windows derived from gnome-terminal do not re-attach as maximized

[stdedos]

During #2649

"Maximized windows derived from gnome-terminal do not re-attach as maximized". I am not sure what further to add.

This is my non-shadow session that I start a gnome-terminal, and then add stuff on-demand.

"Feels" to me as a recent regression, so I'd keep my research around r256** for starters.

I'm fine if you want to solve this by canceling maximized mode during re-attaching (if too complicated to solve).