Fixed importing old database models

Force full restart to trigger the upgrade methods again.

app/src/main/java/de/danoeh/antennapod/activity/ImportExportActivity.java

@@ -160,6 +160,7 @@ public class ImportExportActivity extends AppCompatActivity {
             ComponentName cn = intent.getComponent();
             Intent mainIntent = Intent.makeRestartActivityTask(cn);
             startActivity(mainIntent);
+            Runtime.getRuntime().exit(0);
         });
         d.show();
     }