nitcorn: Non POLA cookie behavior cause lost sessions

[privat]

nitcorn cookies are assigned by path. This cause some issues when tracking sessions

In the following example, the 3 GET cause the creation of 3 distinct sessions

• http://localhost:8080/foo/
• http://localhost:8080/bar/
• http://localhost:8080/

Then, the next GET that revisits foo is given a different session (the one of / is used, but it seems there is some randomness)

• http://localhost:8080/foo/

example: https://gist.github.com/privat/e769dad16423cfcd3c921d603496107e

This cause sessions to be lost and external authentification with a redirect (like github oauth) to fail