T8344: Preserve symlinks when copying config to/from TPM encrypted volume

shutil.copytree() defaults to symlinks=False, so it recurses into
symlinked directories and recreates them as real directories instead
of preserving the symlink.
cloud-init creates /opt/vyatta/etc/config/cloud/instance as a symlink
to instances/i-<id>. Enabling/disabling config encryption copied this
tree with copytree() and silently turned that symlink into a real
directory, causing cloud-init to fail on later runs with:
    IsADirectoryError: [Errno 21] Is a directory: '.../cloud/instance'
Pass symlinks=True to preserve symlinks during the copy.

0 files changed, 0 insertions, 0 deletions