core: Remove an unneeded use warning
@@ -2,6 +2,8 @@ use std;
use std::fmt;
use util::u128;
use byteorder::{BigEndian, ByteOrder};
+// Unneeded since 1.21
+#[allow(unused_imports)]
use std::ascii::AsciiExt;
#[derive(Debug,Copy,Clone,PartialEq,Eq,Hash)]
