fix: #8305, don't use null values

src/upgrades/1.13.3/fix_users_sorted_sets.js

@@ -44,9 +44,9 @@ module.exports = {
 				}
 				totalUserCount += 1;
 				await db.sortedSetAddBulk([
-					['users:joindate', userData.joindate, uids[index]],
-					['users:reputation', userData.reputation, uids[index]],
-					['users:postcount', userData.postcount, uids[index]],
+					['users:joindate', userData.joindate || Date.now(), uids[index]],
+					['users:reputation', userData.reputation || 0, uids[index]],
+					['users:postcount', userData.postcount || 0, uids[index]],
 				]);
 				if (userData.hasOwnProperty('flags') && parseInt(userData.flags, 10) > 0) {
 					await db.sortedSetAdd('users:flags', userData.flags, uids[index]);