remove unnecessarily silenced lint in history

src/builtins/history.rs

@@ -306,8 +306,8 @@ pub fn history(parser: &Parser, streams: &mut IoStreams, args: &mut [&wstr]) ->
                 ));
                 return STATUS_INVALID_ARGS;
             }
-            #[allow(clippy::unnecessary_to_owned)]
-            for delete_string in args.iter().copied() {
+
+            for &delete_string in args {
                 history.remove(delete_string.to_owned());
             }
         }