Fix wrong function names in code doc (#416)

Author: CrazyNorman

src/Solnet.Rpc/IRpcClient.cs

@@ -715,15 +715,15 @@ RequestResult<List<AccountKeyPair>> GetProgramAccounts(string pubKey, Commitment
         /// </summary>
         /// <param name="commitment">The state commitment to consider when querying the ledger state.</param>
         /// <returns>Returns a task that holds the asynchronous operation result and state.</returns>
-        [Obsolete("DEPRECATED: Please use GetLatestBlockhashAsync instead. This method is expected to be removed in solana-core v2.0")]
+        [Obsolete("DEPRECATED: Please use GetLatestBlockHashAsync instead. This method is expected to be removed in solana-core v2.0")]
         Task<RequestResult<ResponseValue<BlockHash>>> GetRecentBlockHashAsync(Commitment commitment = Commitment.Finalized);
 
         /// <summary>
         /// Gets a recent block hash.
         /// </summary>
         /// <param name="commitment">The state commitment to consider when querying the ledger state.</param>
         /// <returns>Returns an object that wraps the result along with possible errors with the request.</returns>
-        [Obsolete("DEPRECATED: Please use GetLatestBlockhash instead. This method is expected to be removed in solana-core v2.0")]
+        [Obsolete("DEPRECATED: Please use GetLatestBlockHash instead. This method is expected to be removed in solana-core v2.0")]
         RequestResult<ResponseValue<BlockHash>> GetRecentBlockHash(Commitment commitment = Commitment.Finalized);
 
         /// <summary>