Return callback with error if an error is emitted on filestore stream.

services/web/app/coffee/Features/FileStore/FileStoreHandler.coffee

@@ -45,6 +45,7 @@ module.exports = FileStoreHandler =
 		readStream = request(opts)
 		readStream.on "error", (err) ->
 			logger.err {err, project_id, file_id, query}, "error in file stream"
+			return callback(err)
 		callback(null, readStream)
 
 	deleteFile: (project_id, file_id, callback)->