Update install script for beta 9 of ts6 server

[LeoKlaus]

The latest beta server for TS6 no longer uses bzip2 compression and the file structure has changed slightly, so the old install script no longer works.

I'm assuming the same changes apply to the ARM version, but I don't have a Pterodactyl instance running on an ARM server to test.

As the diff is not properly displayed due to the install script being compressed to a single line, here are the changes I made:
Line 4:

apt-get install -y jq bzip2

to

apt-get install -y jq xz-utils

Line 22:

url=$(echo "$json" | jq -r '.assets | map(select((.name | contains("linux_amd64")) and (.name | endswith(".tar.bz2"))))[0].browser_download_url')

to

url=$(echo "$json" | jq -r '.assets | map(select((.name | contains("linux-amd64")) and (.name | endswith(".tar.xz"))))[0].browser_download_url')

Line 25:

    echo "Not found: $ver"

to

    echo "No matching archive found: $ver"

(this one is technically not needed but made debugging easier

Line 29:

curl -sSL "$url" | tar xj --strip-components=1

to

curl -sSL "$url" | tar xvJf -