Resolve "SelfsignedKeyCertPair only works with German time format"

Summary

Set standard country for SelfSignedKeyCertPair to empty string "", as there is no reliable way to get the users country.

Explain your context

(Explain what you did.)

Please list breaking changes, new features or bugfixes

• Breaking changes:

• New features:

• Bugfixes:

  • Fix Selfsigned Certificate creation when region is not set to Germany.

Closes #304 (closed)