Create nginx user
Create nginx user

Only relevant when bringing it up from scratch,
so this went undetected until we tried that again...

DarkDimius/scala-jenkins-infra,lrytz/scala-jenkins-infra,DarkDimius/scala-jenkins-infra,adriaanm/scala-jenkins-infra,DarkDimius/scala-jenkins-infra,SethTisue/scala-jenkins-infra,scala/scala-jenkins-infra,adriaanm/scala-jenkins-infra,retronym/scala-jenkins-infra,retronym/scala-jenkins-infra,lrytz/scala-jenkins-infra,scala/scala-jenkins-infra,SethTisue/scala-jenkins-infra,SethTisue/scala-jenkins-infra,adriaanm/scala-jenkins-infra,lrytz/scala-jenkins-infra,retronym/scala-jenkins-infra