Update servers.md

[ThePineappler]

Mysteryshack is outdated

[raucao]

Thanks. As far as I know, mysteryshack does not need updating in order to conform to the current spec version. In fact, it should be fully functional, and personally, I use it locally for app development from time to time with no issues.

Maybe a note about it being unmaintained (and thus not safe to run in production without reviewing security issues of dependencies etc.) makes more sense in this case, because the list of outdated implementations is specifically for the ones that are actually not usable anymore with current client implementations.

[rosano]

the list of outdated implementations is specifically for the ones that are actually not usable anymore with current client implementations.

Maybe "outdated" could be renamed to reflect this, and that the other section is still usable despite being 'old'.