When updating a previously broken plugin, do not show an error message because the previous version of the plugin cannot be loaded

src/calibre/gui2/preferences/plugins.py

@@ -403,7 +403,12 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
             return
 
         all_locations = OrderedDict(ConfigWidget.LOCATIONS)
+        try:
             plugin_action = plugin.load_actual_plugin(self.gui)
+        except:
+            # Broken plugin, fails to initialize. Given that, it's probably
+            # already configured, so we can just quit.
+            return
         installed_actions = OrderedDict([
             (key, list(gprefs.get('action-layout-'+key, [])))
             for key in all_locations])