Merge #57: Scanning fails when birthday block does not exist

c5c22ad fix(cliv2): scanning fails when birthday block does not exist (nymius)

Pull request description:

  When the wallet is just created, there is no blocks on the `LocalChain`, making the request of the birthday checkpoint impossible to serve.

  This change avoids the issue by directly using the height and hash set on the wallet.birthday field.

ACKs for top commit:
  nymius:
    self ACK c5c22ad

Tree-SHA512: 5c9b7f6439858663127bfe7157acdb194b7a449c3aa89273e31956361e7a903b2bc8cbab4d16234a45bc11f25ae4b0d4bbe9fc3a2807be432a1a1436eb8faa95

Author: nymius

cli/v2/src/main.rs

@@ -335,13 +335,7 @@ async fn main() -> anyhow::Result<()> {
                 let hash = wallet.chain().tip().hash();
                 HeaderCheckpoint::new(height, hash)
             } else {
-                let checkpoint = wallet
-                    .chain()
-                    .get(wallet.birthday.height)
-                    .expect("should be something");
-                let height = checkpoint.height();
-                let hash = checkpoint.hash();
-                HeaderCheckpoint::new(height, hash)
+                HeaderCheckpoint::new(wallet.birthday.height, wallet.birthday.hash)
             };
 
             tracing::info!(