pull-updates: Fix pulling new upstream versions
Commit 5802517d "pull-updates: Push all local refs atomically" broke pushing multiple refs when pulling updates (that ism when pulling a new upstream version) due to excessive quoting.
$ git push --follow-tags --atomic ${CI_AUTH_PROJECT_URL} "$BRANCHES"
fatal: invalid refspec 'debian/buster
debian/buster-security
pristine-lfs
upstream/buster'
Let $BRANCH
get expanded to multiple arguments rather than passing all
of them as a single argument.
Edited by Emanuele Aina