Fix breakage due to bool_to_bitflags #963

Job	Run time
Clippy	55s
Rustfmt	12s
Build docs	1m 25s
Test (MSRV)	1m 26s
Test (stable)	2m 9s
Test (beta)	2m 7s
Test (nightly)	2m 12s
Test (macOS)	4m 56s
Test (Windows)	4m 20s
Test (no features)	1m 15s
Test (all features - simdjson, cargo test --all-features --lib --tests --examples)	1m 29s
Test (native TLS, cargo test --all-features --features serenity/native_tls_backend --lib --tests ...	1m 25s
	23m 51s

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