Merge rust-bitcoin#188: rustfmt: Use show_parse_errors

77a5d0e rustfmt: Use show_parse_errors (Jamil Lambert, PhD)

Pull request description:

  Following on from the [comment in rust-bitcoin #3006](rust-bitcoin/rust-bitcoin#3006 (comment)),
  Quoting tcharding (link removed to prevent spamming rustfmt PR):

  > There are no behaviour changes with this patch applied.
  >
  > In rust-lang/rustfmt 5961 the `hide_parse_errors` was changed to `show_parse_errors` with default `true`.
  >
  > Since we run the formatter with nightly we are getting the following warning
  >
  > Warning: the `hide_parse_errors` option is deprecated. Use `show_parse_errors` instead
  >
  > Rename the variable and keep the default value `true`.

ACKs for top commit:
  tcharding:
    ACK 77a5d0e
  clarkmoody:
    ACK 77a5d0e
  apoelstra:
    ACK 77a5d0e

Tree-SHA512: 46ad0450fc857e19c0d5423e81a4cf1d095906ad06bc72f762f9c700436bd03afb6188d0c91ed0d0e088645969b3528841aed84b13f622c5032d8fa294b6714e

rustfmt.toml

@@ -71,7 +71,7 @@ color = "Auto"
 unstable_features = false
 disable_all_formatting = false
 skip_children = false
-hide_parse_errors = false
+show_parse_errors = true
 error_on_line_overflow = false
 error_on_unformatted = false
 emit_mode = "Files"