Recover a repository accidentally converted to a branch

[Adam Glauser]

I did not read the help for `bzr reconfigure --use-shared` closely 
enough, and ran it as `bzr reconfigure --use-shared <path to 
repository>` from a lightweight checkout.  The idea was to try to 
convert the lightweight checkout to a heavyweight checkout without 
having to download the whole history which was mostly in the local 
repository already.

Instead, I now have a hosed up .bzr directory at <path to repository>. 
<path to repository>/.bzr has an empty branch-lock directory, and a 
branch-format file with the contents "Bazaar-NG meta directory, format 1".

Is there a way to recover the repository?