Fixed #20455 -- Do not use ngettext for undefined plurals

Using two separate translation strings instead of gettext plural when
there is no reference to the number in the translated string. This
prevents some translations like Russian and Latvian to use the singular
form for 11 or 21.

django/contrib/admin/templates/admin/auth/user/change_password.html

@@ -24,7 +24,7 @@
 {% if is_popup %}<input type="hidden" name="_popup" value="1" />{% endif %}
 {% if form.errors %}
     <p class="errornote">
-    {% blocktrans count counter=form.errors.items|length %}Please correct the error below.{% plural %}Please correct the errors below.{% endblocktrans %}
+    {% if form.errors.items|length == 1 %}{% trans "Please correct the error below." %}{% else %}{% trans "Please correct the errors below." %}{% endif %}
     </p>
 {% endif %}
 

django/contrib/admin/templates/admin/change_form.html

@@ -41,7 +41,7 @@
 {% if save_on_top %}{% block submit_buttons_top %}{% submit_row %}{% endblock %}{% endif %}
 {% if errors %}
     <p class="errornote">
-    {% blocktrans count counter=errors|length %}Please correct the error below.{% plural %}Please correct the errors below.{% endblocktrans %}
+    {% if errors|length == 1 %}{% trans "Please correct the error below." %}{% else %}{% trans "Please correct the errors below." %}{% endif %}
     </p>
     {{ adminform.form.non_field_errors }}
 {% endif %}

django/contrib/admin/templates/admin/change_list.html

@@ -64,7 +64,7 @@
     {% endblock %}
     {% if cl.formset.errors %}
         <p class="errornote">
-        {% blocktrans count cl.formset.errors|length as counter %}Please correct the error below.{% plural %}Please correct the errors below.{% endblocktrans %}
+        {% if cl.formset.errors|length == 1 %}{% trans "Please correct the error below." %}{% else %}{% trans "Please correct the errors below." %}{% endif %}
         </p>
         {{ cl.formset.non_form_errors }}
     {% endif %}

django/contrib/admin/templates/admin/login.html

@@ -14,7 +14,7 @@
 {% block content %}
 {% if form.errors and not form.non_field_errors and not form.this_is_the_login_form.errors %}
 <p class="errornote">
-{% blocktrans count counter=form.errors.items|length %}Please correct the error below.{% plural %}Please correct the errors below.{% endblocktrans %}
+{% if form.errors.items|length == 1 %}{% trans "Please correct the error below." %}{% else %}{% trans "Please correct the errors below." %}{% endif %}
 </p>
 {% endif %}
 

django/contrib/admin/templates/registration/password_change_form.html

@@ -17,7 +17,7 @@
 <div>
 {% if form.errors %}
     <p class="errornote">
-    {% blocktrans count counter=form.errors.items|length %}Please correct the error below.{% plural %}Please correct the errors below.{% endblocktrans %}
+    {% if form.errors.items|length == 1 %}{% trans "Please correct the error below." %}{% else %}{% trans "Please correct the errors below." %}{% endif %}
     </p>
 {% endif %}
 

django/contrib/comments/templates/comments/preview.html

@@ -8,7 +8,7 @@
   <form action="{% comment_form_target %}" method="post">{% csrf_token %}
     {% if next %}<div><input type="hidden" name="next" value="{{ next }}" /></div>{% endif %}
     {% if form.errors %}
-    <h1>{% blocktrans count counter=form.errors|length %}Please correct the error below{% plural %}Please correct the errors below{% endblocktrans %}</h1>
+    <h1>{% if form.errors|length == 1 %}{% trans "Please correct the error below" %}{% else %}{% trans "Please correct the errors below" %}{% endif %}</h1>
     {% else %}
     <h1>{% trans "Preview your comment" %}</h1>
       <blockquote>{{ comment|linebreaks }}</blockquote>