Patch unblock user for free trail ends

relate #3701+

What does this MR do and why?

if user is blocked and then paid(unblock), then blocked again
user should have two blocked attributes
however due to (user_id, key) unique key in attribute table, we have to change previous attribute
make blocked attribute always be last one

Screenshots or screen recordings

below is the result of block user, unblock user and block user again, you will notice old blocked attribute is override by new blocked attribute

Before	After