fix: insert headers even if they're set-cookie

[dr-frmr]

Problem

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Solution

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Docs Update

Corresponding docs PR

Notes

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[Tenari]

ok I believe these logs verify that the pr #289 does fix it:

Wed 15:36 memedeck:holium.os: GET /v1/auth/logout
Wed 15:36 memedeck:holium.os: proxying http://localhost:8081/v1/auth/logout?
Wed 15:36 memedeck:holium.os: {"sec-ch-ua-platform": "\"macOS\";", "sec-fetch-site": "same-origin;", "sec-gpc": "1;", "sec-ch-ua": "\"Not A(Brand\";v=\"99\", \"Brave\";v=\"121\", \"Chromium\";v=\"121\";", "sec-ch-ua-mobile": "?0;", "cookie": "id=A4liyyO+H5BSfmizG7QEgIQptEJdA1ptAQvT2thlz6gDodDCa0QmV+3Et91+R2mN4SN3QO5i+nD3+PIoBwx7uJrAHXUbDzeEnxQmUGenJAmLJDXyYQSdtAZx6vZMlo8jEGpHY3FKZ4D9gFhzkBVReH%2F+FZrVGKKI0ZWLxZGjbwgOlOq3F83Higyvcmg7O%2Fa2aSe%2FO04L6hDsclfYp2g%3D;", "accept-language": "en-US,en;", "sec-fetch-mode": "cors;", "host": "http://localhost:8080", "accept-encoding": "gzip, deflate, br;", "connection": "keep-alive;", "user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36;", "referer": "http://localhost:8080/memedeck:memedeck:holium.os/home;", "sec-fetch-dest": "empty;", "accept": "*/*;"}
Wed 15:36 memedeck:holium.os: status: 200, headers: {"set-cookie": "id=6msF8I%2FKBcfS13z8sKnjRjAZJLDq19i6I12WjHDa; HttpOnly; SameSite=Lax; Path=/", "content-type": "text/plain; charset=utf-8", "date": "Wed, 27 Mar 2024 20:36:40 GMT", "access-control-expose-headers": "set-cookie, content-type", "vary": "Origin, Access-Control-Request-Method, Access-Control-Request-Headers", "content-length": "2", "access-control-allow-credentials": "true"}