Merge bitcoindevkit/bdk#2043: fix(example_cli): clippy warnings

62da6dc96a37959bc2407b8d60072c4705c40f67 fix(electrum): clippy warnings (Leonardo Lima)
cb6ef76da4b4cb84e27047c41328578a9b5da551 fix(example_cli): clippy warnings (Leonardo Lima)

Pull request description:

  ### Description

  There's some annoying clippy warnings/errors that I'm only facing on the CI and not able to reproduce locally. I'm fixing those here.

  ### Changelog notice

  ```
  ### Changed
  - Update the string formatting in `example_cli`.
  ```

  ### Checklists

  #### All Submissions:

  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)

ACKs for top commit:
  evanlinjin:
    ACK 62da6dc96a37959bc2407b8d60072c4705c40f67

Tree-SHA512: 273e09bbfd841cbbcc0f57e24ae40dd0bcb68523fec684d9e380629ac6b0aab198214f8208fb48e88cfa391b3c6a427d757492da465495301cdfb44d28f6ab8c