Doesn't reserve the correct height when scaling factor is 2

[Darrell Sandstrom]

This in in regards to the x11-rewrite version. I have a hidpi monitor with a resolution of 2560x1440. I use a interface scaling factor of 2 (org.gnome.desktop.interface scaling-factor). Wingpanel doesn't reserve the right height when the scaling factor is not 1. Maximized windows get hidden under the wingpanel, which blocks the window's controls. I tried a scaling factor of 1 and had no problem. Let me know if you need more info.