Update SeniorLauncher, Fixed appcrash when contact list is empty

Sorry for the new request, I found a factory-fresh phone this morning and noticed the app is crashing so i wrote this fix a couple of minutes ago. I assume the linter is not complaining much and the build is working fine since I undestood the basics now I guess :-) It's such a pleasure to see my app now in F-Droid, thank you so much for the help in process.