Quick workaround to fix the Update Cache dialog not showing on close (KDE).

--- a/softwareproperties/kde/SoftwarePropertiesKDE.py
+++ b/softwareproperties/kde/SoftwarePropertiesKDE.py
@@ -700,7 +700,9 @@
   def on_close_button(self):
     """Show a dialog that a reload of the channel information is required
        only if there is no parent defined"""
-    if self.modified_sourceslist == True and self.options.no_update == False:
+    #FIXME:when "self.modified_sourceslist" is working correctly, uncomment the next line and remove the other
+    #if self.modified_sourceslist == True and self.options.no_update == False:
+    if self.userinterface.buttonBox.button(QDialogButtonBox.Reset).isEnabled() == True and self.options.no_update == False:
         messageBox = QMessageBox(self.userinterface)
         messageBox.setIcon(QMessageBox.Information)
         reloadButton = messageBox.addButton(_("Reload"), QMessageBox.AcceptRole)