This adds a new endpoint under `/git-annex-p2phttp` which acts as an
authenticating proxy to git-annex' p2phttp server. This makes it
possible to set `annex+<server-url>/git-annex-p2phttp` as
`remote.<name>.annexurl` and use git-annex fully over http(s) with the
normal credentials and access tokens provided by Forgejo.
Fixes#25.
Reviewed-on: https://codeberg.org/matrss/forgejo-aneksajo/pulls/42
Co-authored-by: Matthias Riße <m.risse@fz-juelich.de>
Co-committed-by: Matthias Riße <m.risse@fz-juelich.de>
