fix: error with crm pack activation notes

CHANGELOG:

### Fixed
- [#917](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/917) Fix error with crm pack activation notes

Related card: -

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Fix singleton error:

      File "/home/odoo/pyenv/versions/3.7.7/envs/odoo/src/odoo12-addon-somconnexio/setup/somconnexio/odoo/addons/somconnexio/models/crm_lead_line.py", line 310, in <listcomp>
        if (other_lead_line.is_fiber and
      File "/opt/odoo/odoo/fields.py", line 1030, in __get__
        record.ensure_one()
      File "/opt/odoo/odoo/models.py", line 4768, in ensure_one
        raise ValueError("Expected singleton: %s" % self)
    ValueError: Expected singleton: crm.lead.line(7700, 7701, 7702)