Fix HTML leak in job_detail

Use `striptags` to strip all html from `og:description`, which was causing HTML to leak.

Resolves #2307

templates/jobs/job_detail.html

@@ -8,7 +8,7 @@
 {% block content_attributes %}with-right-sidebar{% endblock %}
 
 {% block og_title %}Job: {{ object.job_title }} at {{ object.company_name }}{% endblock %}
-{% block og-descript %}{{ object.description|escape|truncatechars:200 }}{% endblock %}
+{% block og-descript %}{{ object.description|striptags|truncatechars:200 }}{% endblock %}
 
 {% block content %}
 {% load companies %}