Release process: be less clever.

I use git@gitlab.tails.boum.org:tails/tails as my remote, and that
code didn't work.

wiki/src/contribute/release_process.mdwn

@@ -946,9 +946,8 @@ before starting the wrapper from `puppet-tails`:
        set -eu
        WORK_DIR=$(mktemp -d)
        TAILS_REMOTE="$(git -C "${RELEASE_CHECKOUT?:}" remote get-url origin)"
-       PUPPET_TAILS_REMOTE=$(echo -n "${TAILS_REMOTE?:}" | perl -p -E 's,:tails(:?[.]git)?\z,:puppet-tails,')
        cd "${WORK_DIR?:}"
-       git clone "$PUPPET_TAILS_REMOTE"
+       git clone git@gitlab-ssh.tails.boum.org:tails/puppet-tails
        sudo -l
        time                                                                   \
        ./puppet-tails/files/jenkins/slaves/isobuilders/wrap_tails_create_iuks \