♻️ Have welcome banner use octoprint.util.version

Cleaner solution for OctoPrint/OctoPrint#4940

Author: foosel

scripts/82-fix-welcome-banner

@@ -0,0 +1,12 @@
+set -x
+set -e
+
+export LC_ALL=C
+
+source /common.sh
+install_cleanup_trap
+
+# if we already have the octopi.txt file updated, we don't need to do anything
+grep -q 'from octoprint._version import' /home/pi/scripts/welcome || exit 0
+
+sed -i 's#^_OCTOPRINT_VERSION=.*$#_OCTOPRINT_VERSION=$($HOME/oprint/bin/python -c "from octoprint.util.version import get_octoprint_version_string; print(get_octoprint_version_string())" || echo "unknown")#' /home/pi/scripts/welcome