Open previously opened databases in correct order

In LastOpenedDatabases, the most recently opened file is listed first and the
least recently opened one is listed last. If the databases are re-opened in this
order, LastOpenedDatabases is reversed afterwards. To avoid this, load the files
in reverse order, so LastOpenedDatabases is not modified.

src/main.cpp

@@ -131,7 +131,8 @@ int main(int argc, char** argv)
     
     if (config()->get("OpenPreviousDatabasesOnStartup").toBool()) {
         const QStringList filenames = config()->get("LastOpenedDatabases").toStringList();
-        for (const QString& filename : filenames) {
+        for (int ii = filenames.size()-1; ii >= 0; ii--) {
+            QString filename = filenames.at(ii);
             if (!filename.isEmpty() && QFile::exists(filename)) {
                 mainWindow.openDatabase(filename, QString(), QString());
             }