build-steps/30_copy-into-img: no backup of /etc/rc.local required anymore, since we do not modify it anymore.
trap ERR TERM INT -> trap ERR
trap ERR TERM INT -> trap ERR
Whonix-Gateway_packages, Whonix-Workstation_packages:
added libgl1-mesa-dri to prevent error (EE) AIGLX error: dlopen of /usr/lib/i386-linux-gnu/dri/swrast_dri.so failed (/usr/lib/i386-linux-gnu/dri/swrast_dri.so: cannot open shared object file: No such file or directory) inn /var/log/Xorg.0.log