As noted by wiz@ (and missed by me in TODO...), 0.9.9.3 was already out.

Update to 0.9.9.3. Nothing much changed between .2 and .3, update is
straightforward.

While here, make MESSAGE more helpful in case of package upgrade.

Changelog:

0.9.9.2 => 0.9.9.3

Functionality Enhancements

    * Bindings available to a principal are now listed in the Admin UI.
    * Attempt to login using supplied basic authentication credentials, if all else fails.

Bug Fixes

    * WebDAV Sync is now supported for Addressbook collections.
    * VCARD resources will no longer report a blank ETag in an XML responses.
    * The ETag property will be properly quoted when appearing an XML response.

Other Changes

    * 412 error responses to PUT for addressbook resources now include useful information.
    * A new temporary configuration option is added to allow use of the old sync-response tag in WebDAV sync for compatibility with the Inverse CardDAV plugin for Lightning.
    * Basic recognition of VLIST resources.

(jym)