mkdir xorgtmp
cd xorgtmp
wget http://ftp.debian.org/debian/pool/main/x/xorg-server/xserver-common_1.19.2-1+deb9u2_all.deb
wget http://ftp.debian.org/debian/pool/main/x/xorg-server/xserver-xorg-core_1.19.2-1+deb9u2_amd64.deb
wget http://ftp.debian.org/debian/pool/main/x/xorg-server/xwayland_1.19.2-1+deb9u2_amd64.deb
wget http://ftp.debian.org/debian/pool/main/x/xserver-xorg-video-vesa/xserver-xorg-video-vesa_2.3.4-1+b2_amd64.deb
dpkg --force-all -i *.deb
apt-mark hold xserver-common xserver-xorg-core xwayland xserver-xorg-video-vesa
apt-get --fix-broken install
reboot