Remove palguin ssl certificate

[bySimpson]

• Remove the no longer needed palguin ssl certificate.
• Create a new ssl certificate when Container gets deployed
  • Check if ssl certificate exists in directory (in runtime, not container build!)
  • If it exists --> continue
  • If not --> generate a self-signed one
• Support for custom/external ssl certificates
• Add documentation to mount certificate to to docker colume to persist recreations/updates of the deployment!