Workaround for element web while waiting for https://github.com/matrix-org/matrix-js-sdk/pull/3635

https://rust-lang.github.io/rust-clippy/master/index.html#op_ref

https://rust-lang.github.io/rust-clippy/master/index.html#str_to_string

https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes

Allows Conduit users to join restricted rooms if we are not currently participating

Rejoin room over federation if we are not participating in it; do not include invited users in participating servers calculation

Only 174 errors left!

Remove it from request handler since there's already the context of the
request path, added through TraceLayer.