Fix accounts_home and login to display no-password correctly.

This fixes the /register/ (accounts_home) and /login/ pages to not
display the login form if login isn’t allowed at the organization level.

templates/zerver/accounts_home.html

@@ -44,6 +44,7 @@ $(function () {
                         configure authentication backends.</p>
                     </div>
                     {% else %}
+                        {% if password_auth_enabled %}
                             <form class="form-inline" id="send_confirm" name="email_form"
                                 action="{{ current_url() }}" method="post">
                                 {{ csrf_input }}
@@ -68,6 +69,7 @@ $(function () {
                             {% if any_oauth_backend_enabled %}
                             <div class="or">or</div>
                             {% endif %}
+                        {% endif %}
 
                         {% if google_auth_enabled %}
                         <div class="register-google">

templates/zerver/login.html

@@ -129,12 +129,13 @@ autofocus('#id_username');
 
                     <button type="submit" name="button" class="full-width">{{ _("Sign in") }}</button>
                 </form>
-                {% endif %}
 
                 {% if any_oauth_backend_enabled %}
                 <div class="or">or</div>
                 {% endif %}
 
+                {% endif %} <!-- if password_auth_enabled -->
+
                 {% if google_auth_enabled %}
                 <div class="login-google">
                     <a href="{{ url('zerver.views.auth.start_google_oauth2') }}">