lxc: bump to 2.1.0

Bump LXC package from 1.1.5 to 2.1.0. Version 2.x includes many
improvements and optimizations.

https://linuxcontainers.org/lxc/news/

Some tools like lxc-top are rewritten in C and are no longer broken and
dependent on lua.

Signed-off-by: Marko Ratkaj <marko.ratkaj@sartura.hr>

utils/lxc/patches/025-remove-unsupported-option.patch

@@ -1,19 +1,24 @@
 --- a/templates/lxc-download.in
 +++ b/templates/lxc-download.in
-@@ -494,15 +494,7 @@ fi
+@@ -505,20 +505,7 @@ fi
  # Unpack the rootfs
  echo "Unpacking the rootfs"
  
 -EXCLUDES=""
 -excludelist=$(relevant_file excludes)
 -if [ -f "${excludelist}" ]; then
--    while read line; do
--        EXCLUDES="$EXCLUDES --exclude=$line"
--    done < $excludelist
+-    while read -r line; do
+-        EXCLUDES="${EXCLUDES} --exclude=${line}"
+-    done < "${excludelist}"
 -fi
 -
+-# Do not surround ${EXCLUDES} by quotes. This does not work. The solution could
+-# use array but this is not POSIX compliant. The only POSIX compliant solution
+-# is to use a function wrapper, but the latter can't be used here as the args
+-# are dynamic. We thus need to ignore the warning brought by shellcheck.
+-# shellcheck disable=SC2086
 -tar  --anchored ${EXCLUDES} --numeric-owner -xpJf \
 +tar --numeric-owner -xpJf \
-     ${LXC_CACHE_PATH}/rootfs.tar.xz -C ${LXC_ROOTFS}
+     "${LXC_CACHE_PATH}/rootfs.tar.xz" -C "${LXC_ROOTFS}"
  
- mkdir -p ${LXC_ROOTFS}/dev/pts/
+ mkdir -p "${LXC_ROOTFS}/dev/pts/"