fix(Contract): fix fiber_linked df to send to OTRS in change tariff
CHANGELOG:
### Fix
- [#963](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/963)
Fix the DF sent to OTRS in change of tariff when break a pack contract.
Related card: https://trello.com/c/eKfYKgBC/1432-proc%C3%A9s-finalitzaci%C3%B3-contracte-ba
Edited by Gerard Funosas