Fix command level ephemeral setting #937

Job	Run time
Build docs	2m 15s
Rustfmt	5s
Test (MSRV)	1m 18s
Clippy	49s
Test (stable)	1m 57s
Test (beta)	2m 7s
Test (nightly)	2m 0s
Test (macOS)	3m 23s
Test (Windows)	5m 31s
Test (no features)	1m 14s
Test (all features - simdjson, cargo test --all-features --lib --tests --examples)	1m 16s
Test (native TLS, cargo test --all-features --features serenity/native_tls_backend --lib --tests ...	1m 20s
	23m 15s

Provide feedback