fall back to checking lower case hash directories in normal repo
Fix a bug that prevented getting content from a repository that started out
as a bare repository, or had annex.crippledfilesystem set, and was
converted to a non-bare repository.
This unfortunately means that inAnnex check gets slowed down by a stat call
in normal repos when the content is not present. Oh well, such is the cost
of backwards compatability with old mistakes.