Update ui tests to 2018 edition

test_suite/tests/ui/remote/wrong_de.stderr

@@ -1,11 +1,11 @@
 error[E0308]: mismatched types
- --> $DIR/wrong_de.rs:8:10
+ --> $DIR/wrong_de.rs:7:10
   |
-8 | #[derive(Deserialize)]
+7 | #[derive(Deserialize)]
   |          ^^^^^^^^^^^ expected u16, found u8
 help: you can cast an `u8` to `u16`, which will zero-extend the source value
   |
-8 | #[derive(Deserialize.into())]
+7 | #[derive(Deserialize.into())]
   |          ^^^^^^^^^^^^^^^^^^
 
 error: aborting due to previous error