Display last name as default for manual Tracker export

- Reset lastTrackerName after autosave, so manual saving still has the
same default

src/autosave.cpp

@@ -237,8 +237,10 @@ void Autosave::saveTrc()
     const auto projectName                        = mPetrack.getProFileName();
     const auto &[autosaveName, finalAutosaveName] = autosaveNamesTrc(projectName);
     const auto trackFileName                      = mPetrack.getTrackFileName();
+    const auto lastTrackerExport                  = mPetrack.getLastTrackerExport();
     mPetrack.exportTracker(autosaveName);
     mPetrack.setTrackFileName(trackFileName);
+    mPetrack.setLastTrackerExport(lastTrackerExport);
 
     // first save to temp file, so crash during saving doesn't corrupt old autosave
     QFile tempAutosave{autosaveName};