TT#56903 Remove apt's auxfiles directory

apt > 1.6 started creating this directory, but older apt versions do not
know how to clean it up. When using a newer host apt than the one that
will be used in the chroot, the chroot apt will be unable to remove it
properly, and will emit a warning.

mmdebstrap was supposedly fixed in version 0.4.0-1, but the code was
inserted before further «apt-get update» calls, so the directory gets
regenerated. We workaround this here for now, after having run
grml-debootstrap which might be calling mmdebstrap depending on the
release.

Change-Id: I13ad1b7ecc9f60414ab7e9222bada10d09baa2ab

templates/scripts/includes/deployment.sh

@@ -1489,6 +1489,12 @@ if [ -n "${FALLBACK_FS}" ] ; then
   mkdir -p "${TARGET}/ngcp-fallback"
 fi
 
+# TT#56903: mmdebstrap 0.4.1-2 does not properly remove this dir.
+if [ -d "${TARGET}/var/lib/apt/lists/auxfiles" ]; then
+  echo "Removing apt's > 1.6 auxfiles directory"
+  rmdir "${TARGET}/var/lib/apt/lists/auxfiles"
+fi
+
 # MT#7805
 if "$NGCP_INSTALLER" ; then
   cat << EOT | augtool --root="$TARGET"