added logging to err domain

services/filestore/app.coffee

@@ -40,6 +40,7 @@ app.use (req, res, next) ->
 		metrics.inc "err.uncaught"
 		setTimeout(->
 			if !res.headerSent
+				logger.log err:err, "sending 500 our as header has not been sent yet for uncaught exception"
 				res.send(500)
 		, 3000)
 		logger = require('logger-sharelatex')