fixed wrong error classes in grp-tabular

grappelli/templates/admin/edit_inline/tabular.html

@@ -45,7 +45,7 @@ <h3 style="display: none;"><b>{{ inline_admin_formset.opts.verbose_name|title }}
                         {% for line in fieldset %}
                             {% for field in line %}
                                 {% if not field.field.is_hidden %}
-                                    <div class="grp-td {{ field.field.name }} {% if field.field.errors %} grp-error{% endif %}">
+                                    <div class="grp-td {{ field.field.name }} {% if field.field.errors %} grp-errors{% endif %}">
                                         {% if field.is_readonly %}
                                             <p class="grp-readonly">{{ field.contents }}</p>
                                         {% else %}