slapos_web_deploy: Ubuntu 20.04 is supported

master/bt5/slapos_web_deploy/PathTemplateItem/web_page_module/deploy_base_setup.txt

@@ -40,7 +40,7 @@ fi
 
 # Warn users who aren't on an explicitly supported distro, but allow them to
 # override check and attempt installation with ``export FORCE=yes``
-if [[ ! ${DISTRO} =~ (jessie|stretch|buster|xenial|bionic|disco|eoan|rhel7) ]]; then
+if [[ ! ${DISTRO} =~ (jessie|stretch|buster|xenial|bionic|eoan|focal|rhel7) ]]; then
     echo "WARNING: this script has not been tested on $DISTRO"
     if [[ "$FORCE" != "yes" ]]; then
         die $LINENO "If you wish to run this script anyway run with FORCE=yes"