[FIX] project: useless project chatter on portal

On the portal, in "/my/projects/x" it is possible to send messages in the
"Message and communication history" section. Those messages are attached
to the project model but it is not possible to access those messages
from the backend. The chatter on the project model is just a dummy
chatter with no message/thread capacities.

As messages are not accessible from the backend, the frontend section is
pretty useless. The section is no more present on v12 either.

opw-1970586

addons/project/views/project_portal_templates.xml

@@ -112,16 +112,6 @@
                     </div>
                 </div>
             </div>
-            <div class="row mt32">
-                <div class="col-md-12">
-                    <h4><strong>Message and communication history</strong></h4>
-                </div>
-                <div class="col-md-10 col-md-offset-1 mt16">
-                    <t t-call="portal.message_thread">
-                        <t t-set="object" t-value="project"/>
-                    </t>
-                </div>
-            </div>
         </t>
     </template>