use show_without_template for correctly render with template_extension

I use Redmine-plantillas-plugin and [Redmine Wiki Extensions Plugin](http://www.r-labs.org/projects/r-labs/wiki/Wiki_Extensions_en)
Redmine-plantillas-plugin didn't use "show_without_template", then redmine-wiki-extension plugin's feature was disabled(such as footnote, etc.).
Simply, use "show_without_template" will fix this issue.