enable logging in i3

replace "Exec=i3" with "Exec=i3 –shmlog-size=26214400" in /usr/share/xsessions/i3.desktop

[Desktop Entry]
Name=i3
Comment=improved dynamic tiling window manager
Exec=i3 --shmlog-size=26214400
TryExec=i3
Type=Application
X-LightDM-DesktopName=i3
DesktopNames=i3

/usr/share/xsessions/i3.desktop