data/defaults: Increase mimetype indexers concurrency to 3
data/defaults: Increase mimetype indexers concurrency to 3

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