Fix retinajs

Author: migueldemoura

_includes/image.html

@@ -1,7 +1,6 @@
-<a href="{% asset '{{ include.path-detail }}' @path %}"
-   data-rjs="{% asset '{{ include.path-detail }}' @path %}"
->
+<a href="{% asset '{{ include.path-detail }}' @path %}">
   <img src="{% asset '{{ include.path }}' @path %}" alt="{{ include.alt }}"
+       data-rjs="{% asset '{{ include.path-detail }}' @path %}"
        data-action="zoom"
        data-zooming-width="{{ assets[include.path-detail].width }}"
        data-zooming-height="{{ assets[include.path-detail].height }}"