Bail out if history API request fails

services/web/app/coffee/Features/History/HistoryController.coffee

@@ -46,9 +46,14 @@ module.exports = HistoryController =
 				"X-User-Id": user_id
 		}, (error, response, body) ->
 			return next(error) if error?
-			HistoryManager.injectUserDetails body, (error, data) ->
-				return next(error) if error?
-				res.json data
+			if 200 <= response.statusCode < 300
+				HistoryManager.injectUserDetails body, (error, data) ->
+					return next(error) if error?
+					res.json data
+			else
+				error = new Error("history api responded with non-success code: #{response.statusCode}")
+				logger.error err: error, user_id: user_id, "error proxying request to history api"
+				next(error)
 
 	buildHistoryServiceUrl: (useProjectHistory) ->
 		# choose a history service, either document-level (trackchanges)