filter_request_header adds a header

[maelle]

See https://github.com/maelle/exemplighratia/pull/2/files

In https://github.com/maelle/exemplighratia/blob/vcrtest/tests/fixtures/gh_api_status.yml there is actually no Authorization header in the HTTP request made, but vcr's filtering adds it. I would have expected vcr to replace the header with the value when the header exists to begin with.

[sckott]

Hmm, not sure off the top. I guess it's a bit of an edge case in that I wouldn't expect a user to filter out a header they think they don't have. But, definitely should be fixed.

[maelle]

Well the configuration is for all tests and you won't have the same headers in all requests so it might actually be quite common?

[sckott]

@maelle fixed now