message: Remove sub-expressions from parsing error
diff: @@ -1589,8 +1589,7 @@ impl fmt::Display for ErrorKind {
  RepeaterExpectsExpr =>
  write!(f, "Missing expression for repetition operator."),
  RepeaterUnexpectedExpr(ref e) =>
  - write!(f, "Invalid application of repetition operator to: \
  - '{}'.", e),
  + write!(f, "Invalid application of repetition operator."),
  UnclosedCaptureName(ref s) =>
  write!(f, "Capture name group for '{}' is not closed. \
  (Missing a '>'.)", s),
  