lfs: gracefully handle aborts on the server when corrupt blobs are detected The aborts weren't killing the server, but this seems cleaner. I'm not sure if it matters to handle the remaining IOError in the test like this, for consistency. The error code still feels wrong (especially if the client is trying to download a corrupt blob) but I don't see anything better in the RFCs, and this is already used elsewhere because the Batch API spec specifically mentioned this as a "Validation Error".

lfs: fix the inferred remote store path when using a --prefix This wasn't appending the '.git/info/lfs' path in this case.