EDIT: thank you F.P.

for those who need complete code:

you need to add below lines to /your_module/__openerp__.py

'qweb': [
    'static/src/xml/base.xml',
],

then you must add xml file /your_module/static/src/xml/base.xml

<?xml version="1.0" encoding="UTF-8"?>

<!-- This will not completely remove debug mode,
        simply will not show debug dropdown to non admin users -->

<templates id="remove_debug" xml:space="preserve">

    <t t-extend="UserMenu.about">
        <t t-jquery="a.oe_activate_debug_mode" t-operation="replace" />
    </t>

    <t t-extend="ViewManagerAction">
        <t t-jquery="select.oe_debug_view" t-operation="replace">
            <select t-if="widget.session.uid === 1 and widget.session.debug" class="oe_debug_view"/>
        </t>
    </t>

</templates>