This function was returning BucketNotFound for all errors
which at least hides the fact that disks could be corrupted.
This commit fixes the behavior by returning all errors that,
are, by the way, Object API errors.
Resource strings and paths are case insensitive on windows
deployments but if user happens to use upper case instead of
lower case for certain configuration params like bucket
policies and bucket notification config. We might not honor
them which leads to a wrong behavior on windows.
This is windows only behavior, for all other platforms case
is still kept sensitive.
