Fix assert with empty setting value

Local value could be empty, so it's important to check it size before read first char.

components/config/gamesettings.cpp

@@ -63,7 +63,7 @@ void Config::GameSettings::validatePaths()
 
     // Do the same for data-local
     QString local = mSettings.value(QString("data-local"));
-    if (local.at(0) == QChar('\"'))
+    if (local.length() && local.at(0) == QChar('\"'))
     {
         local.remove(0, 1);
         local.chop(1);