…ent scheme (dunglas)

This PR was merged into the 2.7 branch.

Discussion
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Namespace generated CSRF tokens depending of the current scheme

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

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Commits
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cdb4271 [Security] Namespace generated CSRF tokens depending of the current scheme