Merge bitcoindevkit/bdk#1264: fix(example_electrum): init LocalChain from genesis

5b7794299308cd81a2ebbe0aa2b1be1d4c47680b fix(example_electrum): init LocalChain from genesis (vmammal)

Pull request description:

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  ### Description

  <!-- Describe the purpose of this PR, what's being adding and/or fixed -->

  This should fix #1252

  ### 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:
  evanlinjin:
    ACK 5b7794299308cd81a2ebbe0aa2b1be1d4c47680b

Tree-SHA512: bf049edb2ba22abb949dfd4cb38608589287f3f374f397c82f778b59c21010daa80b63ad85c442c4ee00a2608f89a8d50447b0db85d15caac7fd0b4fd8956e1a