Change type to long for CLS Compliance

Signed-off-by: Xen <lordofxen@deskasoft.com>

Author: LordOfXen

HashifyNet/Algorithms/XxHash/IXxHashConfig.cs

@@ -38,6 +38,7 @@ public interface IXxHashConfig : IHashConfig<IXxHashConfig>
 		/// Gets the seed value used to populate the secret key.
 		/// <para>If not specified, defaults to 0, which means the default secret key will be used.</para>
 		/// </summary>
-		ulong Seed { get; }
+		long Seed { get; }
 	}
-}
+
+}