Disable pruning for FetchBundle
It turns out that incremental backup bundles do not contain enough information for git to sensibly prune.
This would be a breaking change, but this RPC is only used for "full" backups where purge makes no difference since they are always applied on an empty repository.
There are still a couple of remaining issues:
- Set default branch on restore #3856 (closed)
- Handle deleted refs #3857
Edited by James Fargher