Only allow edit contract email mandate on creation
CHANGELOG:
### Changed
- [#nn](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/nn) Only allow to modify Contract mandate and emails in creation.
We have wizards to change the emails and IBAN(mandate) associated with Contract.
These changes must be synchronized with OC, and we are moving the integration call to the wizards logic.
For this reason we need to disable the edition in these fields.
Edited by Pelayo García