DBGetter & DBInitializer try-with-resources refactoring

[ZivIzhar]

Right now, these warnings are suppressed. This is an important warning which should be treated since it makes sure there will be no leaks.

What to do:

• remove the suppresses
• refactor the code in the way described here : https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html

[ZivIzhar]

Irrelevant, related to merge problems