Set default for ADMIN_OIDC_ALLOW_HTTP to false

[turegjorup]

When following the readme i have seen that projets end up with this line in their .envfile:

ADMIN_OIDC_ALLOW_HTTP=true

This makes the effective default unsafe for production. Having the option to allow HTTP for local use when developing is fine. But it should only be set in .env.local

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.50%. Comparing base (de3ac74) to head (93e8b18).
⚠️ Report is 1 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop      #26   +/-   ##
==========================================
  Coverage      74.50%   74.50%           
  Complexity        54       54           
==========================================
  Files              9        9           
  Lines            255      255           
==========================================
  Hits             190      190           
  Misses            65       65           

Flag	Coverage Δ
unittests	74.50% <ø> (ø)

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