Fix 'This empty block of code can be removed.' issue in app\src\main\java\com\brainer\itmmunity\preference\Preference.kt

[CodeFactor](https://www.codefactor.io/repository/github/brainer3220/itmmunity) found an issue: This empty block of code can be removed.

It's currently on:
[app\src\main\java\com\brainer\itmmunity\preference\Preference.kt:15](https://www.codefactor.io/repository/github/brainer3220/itmmunity/source/master/app/src/main/java/com/brainer/itmmunity/preference/Preference.kt#L15)