Remove .to_string() since BlockHash impls Debug

Author: gcomte

src/async.rs

@@ -115,7 +115,7 @@ impl AsyncClient {
 
     /// Get a [`BlockHeader`] given a particular block height.
     pub async fn get_header(&self, block_height: u32) -> Result<BlockHeader, Error> {
-        let block_hash = self.get_block_hash(block_height).await?.to_string();
+        let block_hash = self.get_block_hash(block_height).await?;
 
         let resp = self
             .client

src/blocking.rs

@@ -128,7 +128,7 @@ impl BlockingClient {
 
     /// Get a [`BlockHeader`] given a particular block height.
     pub fn get_header(&self, block_height: u32) -> Result<BlockHeader, Error> {
-        let block_hash = self.get_block_hash(block_height)?.to_string();
+        let block_hash = self.get_block_hash(block_height)?;
 
         let resp = self
             .agent