Fix OC staging password encrypted value

Last encrypted value (https://gitlab.com/coopdevs/odoo-somconnexio-inventory/-/merge_requests/67) caused this error when provisioning the staging server:

TASK [coopdevs.odoo-role : Set environment variables default file] *********************************************************************************************
Tuesday 24 August 2021  08:53:38 +0200 (0:00:01.550)       0:00:40.785 ********
fatal: [staging-odoo.somconnexio.coop]: FAILED! => {"changed": false, "msg": "AnsibleVaultError: Decryption failed (no vault secrets were found that could decrypt)"}

In here, we encrypt again the new OC admin password found in bitwarden with name 'stagingopencell.coopdevs.org', updated on august 10.