Odoo 10 : Remove or disable the New Message function

Question

Can somebody give a hint how to remove/disable the New message button in contacts module??It doesnt seem to be part of form view.

Answer 1

Found a way to remove the button .Added a new template to add the css:

<openerp>
    <data>
    <!-- Adds all assets in Odoo -->
        <template id="assets_backend" name="contacts assets" inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
        <!--These links will be called when loading your Odoo -->
                <link rel="stylesheet" href="/contacts_custom/static/css/css.css"/> 

            </xpath>
        </template>
    </data>
</openerp>

And the css is :

.o_chatter_button_new_message
                {
                display:none !important;
                }