minor #12634 remove gender-related terms from HTTP fundamentals diagrams (Ioni14)

This PR was merged into the 3.4 branch.

Discussion
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remove gender-related terms from HTTP fundamentals diagrams

In order to make Symfony gender-agnostic, here two reviewed HTTP fundamentals diagrams.

I added, like the old ones, the watermark `www.websequencediagrams.com`, and compressed with `tinypng` webapp (so, no EXIF metadata).

Commits
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a14d99f remove gender-related terms from HTTP fundamentals diagrams

Author: OskarStark