Fix handling of Web calendars

- handle Web calendars that require authentication;
- properly save the "reload on login" option;
- reload Web calendars when clicking on the reload button on top of the
  events/tasks list;
- properly activate the checkbox of new calendars (as they are enabled
  by default).

Fixes #3326

UI/Common/UIxFolderActions.m

@@ -193,8 +193,7 @@
   NSString *folderName;
 
   [self _setupContext];
-  folderSubscription
-    = [moduleSettings objectForKey: @"InactiveFolders"];
+  folderSubscription = [moduleSettings objectForKey: @"InactiveFolders"];
   if (!folderSubscription)
     {
       folderSubscription = [NSMutableArray array];