RavenDB-2835 Fixing parsing issue which caused that after using a commit point to restore index we always set LastIndexedEtag to Etag.Empty because of missing EtagJsonConverter. That in turns caused we reindexed the whole index from scratch.
Merge pull request #1491 from arekais/RavenDB-2835

RavenDB-2835 Fixing parsing issue which caused that after using a commit...