Changed logic of using "Blocked" and "Blocked till" user field.

Change logic to more comfortable when system checks both fields:
 - "Blocked"
 - "Blocked till/from"
Because now when field block is not marked but field blocked till field, user
still stays blocked. It's pretty unlogical.

Signed-off-by: Indomian <egor.b@fabricasaitov.ru>