title: ODOO 10 related field not updated
body: <p>This related field working fine in <code>odoo 9</code>, but not in <code>odoo 10</code>. The field <code>customer_id</code> not updated when I create a new record with <code>nomor_hp_id</code>.</p>
  
  <pre class="lang-py prettyprint-override"><code>nomor_hp_id = fields.Many2one(
      string='Nomor hp',
      comodel_name='nomor.hp',
      ondelete='cascade',
  )
  customer_id = fields.Many2one(
      string='Customer',
      related='nomor_hp_id.customer_id',
      ondelete='cascade',
      store=True,
      readonly=True,
  )
  </code></pre>
  
  <p>Try to start new database but the result still not updated.</p>