Avoid $parsing errors of angular

Even though expressions aren't executed inside textareas, they appear to
be parsed by angular, causing a syntax error when including a page.

app/views/my_projects_overviews/_block_textilizable.html.erb

@@ -51,7 +51,7 @@ See doc/COPYRIGHT.md for more details.
           </div>
           <div class="form--field -required">
             <%= styled_label_tag "textile_#{block_name}", t('info_custom_text') %>
-            <div class="form--field-container">
+            <div class="form--field-container" ng-non-bindable>
               <%= styled_text_area_tag "textile_#{block_name}", textile.html_safe, cols: 40, rows: 5, class: 'wiki-edit' %>
             </div>
           </div>