playbook/re6st: update registry and improve installer

- Update registry to new production registry
( https://re6st-registry.nxdcdn.com/ )
- Create /etc/re6stnet if needed
6 jobs for master in 0 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  External
passed ERP5.StandaloneDeploymentScriptTest-Debian.Bullseye

00:44:51

passed ERP5.StandaloneDeploymentScriptTest-Debian.Buster

00:48:24

passed SlapOS-Master.StandaloneDeploymentScriptTest-Debian.Bullseye

00:36:53

passed SlapOS-Master.StandaloneDeploymentScriptTest-Debian.Buster

00:32:12

passed Wendelin.StandaloneDeploymentScriptTest-Debian.Bullseye

00:37:07

passed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster

00:43:02