Remove unused imports and Fix for 1.22

Author: yuntai

fuzz/fuzz_targets/msg_accept_channel_target_writeable.rs

@@ -30,7 +30,6 @@ pub fn do_test(data: &[u8]) {
 		let enc = msg2.encode();
 		assert_eq!(p, enc.len());
 		assert_eq!(&data[..p], &enc[..]);
-			
 	}
 }
 

src/util/ser.rs

@@ -1,13 +1,11 @@
 use std::result::Result;
-use std::io::{self, Read, Write};
-use std::fmt;
+use std::io::{Read, Write};
 use std::collections::HashMap;
 use std::hash::Hash;
 use std::mem;
 
 use secp256k1::Secp256k1;
 use secp256k1::key::PublicKey;
-use bitcoin::blockdata::script::Script;
 use bitcoin::util::hash::Sha256dHash;
 use std::marker::Sized;
 use ln::msgs::DecodeError;
@@ -269,7 +267,7 @@ impl<W, T> Writeable<W> for Option<T>
 {
 	#[inline]
 	fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
-		if let Some(data) = self {
+		if let &Some(ref data) = self {
 			data[..].write(w)?;
 		} else {
 			0u16.write(w)?;