fix redis warnings

src/database/redis/hash.js

@@ -14,7 +14,7 @@ module.exports = function (redisClient, module) {
 		}
 
 		Object.keys(data).forEach(function (key) {
-			if (data[key] === undefined) {
+			if (data[key] === undefined || data[key] === null) {
 				delete data[key];
 			}
 		});
@@ -26,6 +26,9 @@ module.exports = function (redisClient, module) {
 
 	module.setObjectField = function (key, field, value, callback) {
 		callback = callback || function () {};
+		if (!field) {
+			return callback();
+		}
 		redisClient.hset(key, field, value, function (err) {
 			callback(err);
 		});

src/socket.io/admin/categories.js

@@ -85,7 +85,7 @@ Categories.setPrivilege = function (socket, data, callback) {
 		events.log({
 			uid: socket.uid,
 			ip: socket.ip,
-			privilege: data.privilege,
+			privilege: data.privilege.toString(),
 			action: data.set ? 'grant' : 'rescind',
 			target: data.member,
 		}, callback);