NEW:add network test entry when has network error

Change-Id: Ie315191e26148e520d3e8e3e4323fd619efb982a

src/slic3r/GUI/Jobs/Job.hpp

@@ -47,6 +47,8 @@ protected:
 
     void update_percent_finish();
 
+    void show_networking_test();
+
     bool was_canceled() const { return m_canceled.load(); }
 
     // Launched just before start(), a job can use it to prepare internals