Make settings file recovery more robust

We should not blindly remove the leftover settings file, as the following write()
operation could fail and the user would lost all settings.
We should try renaming it instead.

src/base/settingsstorage.cpp

@@ -241,8 +241,12 @@ QVariantHash TransactionalSettings::read()
                 .arg(Utils::Fs::toNativePath(newPath))
             , Log::WARNING);
 
-        Utils::Fs::forceRemove(newPath);
-        write(res);
+        QString finalPath = newPath;
+        int index = finalPath.lastIndexOf("_new", -1, Qt::CaseInsensitive);
+        finalPath.remove(index, 4);
+
+        Utils::Fs::forceRemove(finalPath);
+        QFile::rename(newPath, finalPath);
     }
     else {
         deserialize(m_name, res);