Mark Bionic as host EOS (#2316)

* Mark Bionic as host EOS

* Update README.md

Co-authored-by: Igor Pečovnik <igorpecovnik@users.noreply.github.com>

README.md

@@ -37,7 +37,7 @@ build tools</h3>
 ## What do you need to get started?
     
 - x64 machine with at least 2GB of memory and ~35GB of disk space for the VM, container or native OS,
-- Ubuntu Bionic 18.04 / Focal 20.04 x64 for native building or any [Docker](https://docs.armbian.com/Developer-Guide_Building-with-Docker/) capable x64 Linux for containerised,
+- Ubuntu Focal 20.04 x64 for native building or any [Docker](https://docs.armbian.com/Developer-Guide_Building-with-Docker/) capable x64 Linux for containerised,
 - superuser rights (configured sudo or root access).
 
 <p align=right><a href=#table-of-contents>⇧</a></p>

lib/general.sh

@@ -990,12 +990,12 @@ prepare_host()
 	display_alert "Build host OS release" "${codename:-(unknown)}" "info"
 
 	# Ubuntu Focal x86_64 is the only fully supported host OS release
-	# Ubuntu Bionic x86_64 support is legacy until it breaks
+	# Ubuntu Bionic x86_64 support is no longer supported
 	# Using Docker/VirtualBox/Vagrant is the only supported way to run the build script on other Linux distributions
 	#
 	# NO_HOST_RELEASE_CHECK overrides the check for a supported host system
 	# Disable host OS check at your own risk, any issues reported with unsupported releases will be closed without a discussion
-	if [[ -z $codename || "bionic buster groovy focal debbie tricia ulyana" != *"$codename"* ]]; then
+	if [[ -z $codename || "buster groovy focal debbie tricia ulyana" != *"$codename"* ]]; then
 		if [[ $NO_HOST_RELEASE_CHECK == yes ]]; then
 			display_alert "You are running on an unsupported system" "${codename:-(unknown)}" "wrn"
 			display_alert "Do not report any errors, warnings or other issues encountered beyond this point" "" "wrn"