Our automated repository checks [1] have detected that the 'hanno' repository can not be synced. The following URIs are listed for the repository: [ svn] https://svn.hboeck.de/overlay/ Please verify that the server hosting the repository is working correctly. If the repository has been moved to a new location or removed altogether, please let us know to update the record appropriately. We reserve the right to remove the repository if we do not receive any reply within 2 weeks. [1]:https://wiki.gentoo.org/wiki/Project:Repository_mirror_and_CI
FYI, this is most likely due to recent ca-certificates change, i.e. most of Gentoo users won't be able to access it if they're using defaults.
The repository has been removed, rendering this bug obsolete.