Fix 'An opening curly bracket must not be followed by a blank line.' issue in samples\EasyCron.Sample\Startup.cs

[CodeFactor](https://www.codefactor.io/repository/github/furkandeveloper/easycronjob) found an issue: An opening curly bracket must not be followed by a blank line.

It's currently on:
[samples\EasyCron.Sample\Startup.cs:30](https://www.codefactor.io/repository/github/furkandeveloper/easycronjob/source/master/samples/EasyCron.Sample/Startup.cs#L30)