allow downgrade on 02 apt upgrade

Signed-off-by: Markus Storm <markus.storm@gmx.net>

Author: mstormi

functions/system.bash

@@ -34,7 +34,7 @@ system_upgrade() {
   export DEBIAN_FRONTEND=noninteractive
   if ! apt-get clean --yes -o DPkg::Lock::Timeout="$APTTIMEOUT"; then echo "FAILED"; return 1; fi
   # bad packages may require interactive input despite of this setting so do not mask output (no cond_redirect)
-  if ! apt-get upgrade --yes -o DPkg::Lock::Timeout="$APTTIMEOUT" -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"; then echo "FAILED"; return 1; fi
+  if ! apt-get upgrade --yes --allow-downgrades -o DPkg::Lock::Timeout="$APTTIMEOUT" -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"; then echo "FAILED"; return 1; fi
   if ! cond_redirect java -version &> /dev/null; then
     update_config_java "Temurin21" && java_install "Temurin21"
   fi