Fix 'The code must not contain multiple blank lines in a row.' issue in API.Boilerplate.Domain\Services\ServiceUsuario.cs

[CodeFactor](https://www.codefactor.io/repository/github/devcomputaria/apiboilerplate) found an issue: The code must not contain multiple blank lines in a row.

It's currently on:
[API.Boilerplate.Domain\Services\ServiceUsuario.cs:32](https://www.codefactor.io/repository/github/devcomputaria/apiboilerplate/source/main/API.Boilerplate.Domain/Services/ServiceUsuario.cs#L32)