vault: use quotes around SWH_WORKER_INSTANCE
vault: use quotes around SWH_WORKER_INSTANCE

SoftwareHeritage/puppet-swh-site,SoftwareHeritage/puppet-swh-profile,SoftwareHeritage/puppet-swh-profile,SoftwareHeritage/puppet-swh-site,SoftwareHeritage/puppet-swh-site,SoftwareHeritage/puppet-swh-profile,SoftwareHeritage/puppet-swh-profile,SoftwareHeritage/puppet-swh-site,SoftwareHeritage/puppet-swh-site,SoftwareHeritage/puppet-swh-profile