20341a3ca1ab85ad77e022b5028136a635c3f42c fix: typo on `SignedAmount` instead of `Amount` (Leonardo Lima) Pull request description: <!-- You can erase any parts of this template not applicable to your Pull Request. --> ### Description It fixes the typo on the `expect()` message introduced on #1426, noticed at https://github.com/bitcoindevkit/bdk/pull/1426#discussion_r1626761825 <!-- Describe the purpose of this PR, what's being adding and/or fixed --> ### Checklists #### All Submissions: * [x] I've signed all my commits * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md) * [x] I ran `cargo fmt` and `cargo clippy` before committing ACKs for top commit: storopoli: ACK 20341a3ca1ab85ad77e022b5028136a635c3f42c notmandatory: ACK 20341a3ca1ab85ad77e022b5028136a635c3f42c Tree-SHA512: 62deb7308b2a6891eeb4598ebdf3c5ee1541fc52fd454bca2816b819bd7f6ab25c18e10c4166c80c4e553bcb3ce2207323376d260484a956837ac857854cbd6b