[FIX] website: make company required on website config

Before this commit, There would be a crash if the user tries to remove `website_company_id` from Website configuration as It is used in Backend.

With this commit, we make `website_company_id` required if the Website is set.

Fixes odoo#47967

closes odoo#48064

X-original-commit: 940cc76
Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>

addons/website/views/res_config_settings_views.xml

@@ -68,7 +68,7 @@
                                     <div class="text-muted">
                                         The company this website belongs to
                                     </div>
-                                    <field name="website_company_id"/>
+                                    <field name="website_company_id" attrs="{'required': [('website_id', '!=', False)]}" />
                                 </div>
                             </div>
                             <div class="col-12 col-lg-6 o_setting_box" id="languages_setting">