The ugettext_lazy method has been deprecated since Django 3.0[1].
This was already replaced in Horizon repo by [2].
[1] https://docs.djangoproject.com/en/3.0/releases/3.0/#id3
[2] cd7c1b5110fe1f64cd9dfbeb1072b37912d0efee
Change-Id: I4ba3ab420cbe508ff4c2014092ef08374d58988b