data/defaults: add swh_loader_git to default instances
data/defaults: add swh_loader_git to default instances

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