remove last comma forloop django
{% for product_in_series in series.get_products %}{%spaceless%}
{% with product_in_series.product as product %}
{%if not forloop.first%}
"<img src='{% version product.get_overview 'page_image' %}'>"
{%if not forloop.last%},{%endif%}
{%endif%}
{% endwith %}
{%endspaceless%}{% endfor %}