fix(electrum): clippy warnings #274

Job	Run time
prepare	4s
Rust fmt	13s
Check no_std	40s
Build & Test (1.88.0, true, --no-default-features --features miniscript/no-std,bdk_chain/hashbrown)	1m 58s
Build & Test Examples (example_cli)	37s
Build & Test (1.63.0, --no-default-features --features miniscript/no-std,bdk_chain/hashbrown)	7m 44s
Build & Test (1.63.0, --all-features)	8m 45s
Rust clippy	1m 16s
Build & Test (1.88.0, true, --all-features)	3m 32s
Build & Test (1.75.0, --no-default-features --features miniscript/no-std,bdk_chain/hashbrown)	2m 15s
Build & Test (1.75.0, --all-features)	4m 11s
Build & Test Examples (example_bitcoind_rpc_polling)	43s
Check WASM	1m 58s
Build & Test Examples (example_electrum)	1m 1s
Build & Test Examples (example_esplora)	57s
	35m 54s

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