Merge rust-bitcoin/rust-miniscript#770: Update deprecated field in rustfmt.toml

b5a8374eb0f59dac0616a6f2600a2cf08fd8f98b Update deprecated field in rustfmt.toml (Sexosexosexo)

Pull request description:

  This fixes the "Warning: the `version` option is deprecated. Use `style_edition` instead." that we see when running `cargo +nightly fmt`.

  The 2021 edition is the last one matching the version "One".

ACKs for top commit:
  apoelstra:
    ACK b5a8374eb0f59dac0616a6f2600a2cf08fd8f98b; successfully ran local tests; thanks!

Tree-SHA512: 8ee0da46a210c59034791d0a46b368fd844b8d32f145be9e37e760162d6198797c98cedb9dd159cbf3b10c8f4144b971b63febbc21801b0c2c1a97461bbc63b6

Author: heap-coder

rustfmt.toml

@@ -53,7 +53,7 @@ match_block_trailing_comma = false
 blank_lines_upper_bound = 1
 blank_lines_lower_bound = 0
 edition = "2018"
-version = "One"
+style_edition = "2021"
 inline_attribute_width = 0
 format_generated_files = true
 merge_derives = true