fix: Fixed the lose of parts on spare part window when open new pzw file

src/picsimlab1.cc

@@ -627,6 +627,7 @@ CPWindow1::_EvOnDestroy(CControl * control)
 
 
  sprintf (fname, "%s/parts_%s.pcf", home, boards_list[lab_].name_);
+ 
  Window5.SaveConfig (fname);
  Window5.DeleteParts ();
 

src/picsimlab5.cc

@@ -285,6 +285,9 @@ CPWindow5::SaveConfig(String fname)
  String temp;
 
  CStringList prefs;
+ 
+ if (GetWin () == NULL)return 0;
+ 
  prefs.Clear ();
 
  temp.Printf ("scale,0,0:%f", scale);