update qmake file

sources/mainwindow.cpp

@@ -104,6 +104,10 @@ void MainWindow::open_save() {
     delete file;
 
     QJsonObject obj = QJsonDocument::fromJson(json.toUtf8()).object();
+    if (obj[KEY_SAVE_FILE_VERSION] != SAVE_FILE_VERSION) {
+        panic_dialog("Your save file version does not match the supported version."
+                     " Please update this file and restart the application");
+    }
     week_template = Week::from_json(obj[KEY_TEMPLATE].toObject());
     QJsonArray arr = obj[KEY_YEARS].toArray();
     foreach (QJsonValue val, arr) {