Cannot clear white / black list

[ghost]

No action is taken if a previously non-empty white / black list is cleared and updated, the previous contents persist.

Reproduction steps:

1. Open Edit Algo page in web app
2. Clear any previously non-empty whitelist or blacklist
3. Click the Update button

Expected behavior:

White / blacklist which was cleared is now cleared after update

Actual behavior:

White / blacklist contents do not change

[ghost]

Confirmed fixed