Few typos and clippy fixes (#1362)

* fix typos

* clippy fixes

bridges/relays/lib-substrate-relay/src/conversion_rate_update.rs

@@ -280,7 +280,7 @@ where
 					genesis_hash,
 					signer: transaction_params.signer,
 					era: TransactionEra::new(best_block_id, transaction_params.mortality),
-					unsigned: UnsignedTransaction::new(call.into(), transaction_nonce).into(),
+					unsigned: UnsignedTransaction::new(call.into(), transaction_nonce),
 				})?
 				.encode(),
 			))

bridges/relays/lib-substrate-relay/src/messages_target.rs

@@ -192,7 +192,7 @@ where
 			.inbound_lane_data(id)
 			.await?
 			.map(|data| data.relayers)
-			.unwrap_or_else(|| VecDeque::new());
+			.unwrap_or_else(VecDeque::new);
 		let unrewarded_relayers_state = bp_messages::UnrewardedRelayersState {
 			unrewarded_relayer_entries: relayers.len() as _,
 			messages_in_oldest_entry: relayers