message: remove spurious fmt::Display instance
diff: @@ -97,18 +97,6 @@ impl fmt::Display for Val {
  }
  }
  -// implement display for anything which implements Pretty
  -impl fmt::Display for Pretty {
  - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  - fmt_pretty(
  - &self.to_pretty(),
  - f,
  - DISPLAY_INDENT_SIZE,
  - DISPLAY_INDENT_LEVEL,
  - )
  - }
  -}
  -
  // the rest of the file is `impl` and `test`
  impl Pretty for str {
  