also delete log and chart window when loading a new file

tools/lammps-gui/lammpsgui.cpp

@@ -635,11 +635,19 @@ void LammpsGui::open_file(const QString &fileName)
         delete slideshow;
         slideshow = nullptr;
     }
-    update_variables();
     if (imagewindow) {
         delete imagewindow;
         imagewindow = nullptr;
     }
+    if (chartwindow) {
+        delete chartwindow;
+        chartwindow = nullptr;
+    }
+    if (logwindow) {
+        delete logwindow;
+        logwindow = nullptr;
+    }
+    update_variables();
     lammps.close();
 }