adding background modifier class

opentech/public/search/templates/search/search.html

 {% extends "base.html" %}
 {% load static wagtailcore_tags wagtailsearchpromotions_tags %}
-
-{% block body_class %}template-searchresults{% endblock %}
-
+{% block body_class %}template-searchresults light-grey-bg{% endblock %}
 {% block title %}{% if search_query %}Search results for “{{ search_query }}”{% else %}Search{% endif %}{% endblock %}
 
 {% block content %}