single_login/views/custom_template.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
<data>

<!-- Changes login page error text -->
<template id="web_login_extended" inherit_id="web.login">
	<xpath expr="//p[@t-if='error']" position="replace">
		<p class="alert alert-danger" t-if="error">
			<t t-esc="error"/>
			<br/><t t-esc="error2"/>
			<br/><t t-esc="error3"/>
		</p>
	</xpath>
</template>

</data>
</openerp>