[FIX] website_mass_mailing: translate button

The text was in a value tag, making it untranslatable

Closes odoo/odoo#30774

Signed-off-by: Martin Trigaux (mat) <mat@odoo.com>

addons/website_mass_mailing/i18n/website_mass_mailing.pot

@@ -81,6 +81,11 @@ msgstr ""
 msgid "Mailing Subscriptions"
 msgstr ""
 
+#. module: website_mass_mailing
+#: model:ir.ui.view,arch_db:website_mass_mailing.unsubscribe
+msgid "Update my subscriptions"
+msgstr ""
+
 #. module: website_mass_mailing
 #. openerp-web
 #: code:addons/website_mass_mailing/static/src/js/website_mass_mailing.editor.js:22
@@ -166,4 +171,3 @@ msgstr ""
 #: model:ir.ui.view,arch_db:website_mass_mailing.s_newsletter_subscribe_popup
 msgid "your email..."
 msgstr ""
-

addons/website_mass_mailing/views/unsubscribe_templates.xml

@@ -28,7 +28,7 @@
                             </ul>
 
                             <div class="text-center mb16">
-                                <input type="submit" id="send_form" class="btn btn-primary" value="Update my subscriptions"/>
+                                <button type="submit" id="send_form" class="btn btn-primary">Update my subscriptions</button>
                             </div>
                         </t>