Remove error handling code when no errors

`ok.html` is only used if the file has no errors. Therefore there will
never been any need to highlight which rows in the file have errors.

app/templates/views/check/ok.html

@@ -59,7 +59,7 @@
         ] + recipients.column_headers
       ) %}
         {% call index_field() %}
-          <span class="{% if item.index in recipients.rows_with_errors %}table-field-error{% endif %}">
+          <span>
             {{ item.index + 2 }}
           </span>
         {% endcall %}