Remove legacy registration templates

aleksis/core/templates/registration/logged_out.html

-{% include 'partials/header.html' %}
-
-<main>
-  <p class="flow-text">Du bist nun abgemeldet.</p>
-  <a href="{% url 'login' %}">Wieder anmelden?</a>
-</main>
-
-{% include 'partials/footer.html' %}

aleksis/core/templates/registration/login.html

-{# -*- engine:django -*- #}
-{% extends "core/base.html" %}
-{% load material_form i18n %}
-
-{% block content %}
-  {% if next %}
-    {% if user.is_authenticated %}
-      <p>
-        Your account doesn't have access to this page. To proceed,
-        please login with an account that has access.
-      </p>
-    {% else %}
-      <p>Please login to see this page.</p>
-    {% endif %}
-  {% endif %}
-
-  <form method="post" action="{% url 'login' %}">
-    {% csrf_token %}
-    {% form form=form %}{% endform %}
-    <button type="submit" class="btn waves-effect waves-light green">
-      {% blocktrans %}Login{% endblocktrans %}
-    </button>
-  </form>
-{% endblock %}