Upgrade snappy-java to 1.1.1.5

We should upgrade snappy-java to 1.1.1.5 across all of our maintenance branches. This release improves error messages when attempting to deserialize empty inputs using SnappyInputStream (this operation is always an error, but the old error messages made it hard to distinguish failures due to empty streams from ones due to reading invalid / corrupted streams); see https://github.com/xerial/snappy-java/issues/89 for more context.

This should be a major help in the Snappy debugging work that I've been doing.