[FIX] website_mass_mailing: use the correct action to obtain token

Before this commit the "subscribe to newsletter" form was using the
action of the website form to obtain its reCaptcha token, while the
validation of the token was done on a specific subscribe action.

After this commit the "subscribe to newsletter" form is using its own
action that matches the one used for validation.

Fixes https://github.com/odoo/odoo/issues/62504

closes odoo/odoo#62728

X-original-commit: 82b06dc4c3df502c8e006169f4ee0f6aa33e3ac1
Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>

addons/website_mass_mailing/static/src/js/website_mass_mailing.js

@@ -79,7 +79,7 @@ publicWidget.registry.subscribe = publicWidget.Widget.extend({
             return false;
         }
         this.$target.removeClass('o_has_error').find('.form-control').removeClass('is-invalid');
-        const tokenObj = await this._recaptcha.getToken('website_form');
+        const tokenObj = await this._recaptcha.getToken('website_mass_mailing_subscribe');
         if (tokenObj.error) {
             self.displayNotification({
                 type: 'danger',