Show empty ringtone name in case of RuntimeException

Fixes #116

app/src/main/java/org/isoron/uhabits/fragments/SettingsFragment.java

@@ -134,6 +134,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
     private void updateRingtoneDescription()
     {
         String ringtoneName = ReminderHelper.getRingtoneName(getContext());
+        if(ringtoneName == null) return;
         Preference ringtonePreference = findPreference("reminderSound");
         ringtonePreference.setSummary(ringtoneName);
     }

app/src/main/java/org/isoron/uhabits/helpers/ReminderHelper.java

@@ -144,7 +144,10 @@ public class ReminderHelper
         fragment.startActivityForResult(intent, requestCode);
     }
 
+    @Nullable
     public static String getRingtoneName(Context context)
+    {
+        try
         {
             Uri ringtoneUri = getRingtoneUri(context);
             String ringtoneName = context.getResources().getString(R.string.none);
@@ -161,4 +164,10 @@ public class ReminderHelper
 
             return ringtoneName;
         }
+        catch (RuntimeException e)
+        {
+            e.printStackTrace();
+            return null;
+        }
+    }
 }