Don't update password policy during nextcloud update

[AceSlash]

In previous Nextcloud version, "Minimum password length" was at 8.

During an update (I think during NC 21 => NC 22), this was changed to 10 and automatically changed on all my instances.

I understand that for the majority of people, this is good, but since this also apply to share links #117, this did break automated systems generating share links.

I also cannot find a release note highlighting this change, and the documentation itself is wrong in this case #299 .

In the future, you may want to change this value to something else like 12 characters, etc. I really don't want to have to react to an undocumented change like this again and have to modify the settings on all kind of instances to make some automated share feature work again.

So please, at least until #117 is fixed, do not arbitrary change the Password policy of running instance.