GO-124 Fix removing SignatureRequested Tag from MessageThread

[jsuchal]

Tomuto uplne nerozumiem. Co toto riesi? Na taketo onetime fixy mozeme aj cez konzolu ci?

[luciajanikova]

Nie je to iba onetime fix, upravuje to aj logiku tejto metody: https://github.com/slovensko-digital/govbox-pro/blob/c07e647d0b63e2a1d0f31c79cf05fa4163887e30/app/models/message_object.rb#L154-L161