Update docs/3_guides/1.2_SDK_api_reference.md

Author: MarcosNicolau

docs/3_guides/1.2_SDK_api_reference.md

@@ -510,7 +510,7 @@ pub async fn get_unlock_block_time(
 
 #### Returns
 
-- `Result<u64, errors::BalanceError>` - The timestamp when the user's balance will be unlocked (as u64).
+- `Result<u64, errors::BalanceError>` - The timestamp when the user's balance will be unlocked.
 
 #### Description