Clean XSS in lms template

AUTHORS

@@ -290,3 +290,4 @@ Matt Tuchfarber <mtuchfarber@edx.org>
 Stuart Young <syoung@edx.org>
 Michael Youngstrom <myoungstrom@edx.org>
 Sahar Markovich <sahar.markovich@gmail.com>
+Asad Azam <asadazam93@gmail.com>

openedx/core/djangoapps/debug/views.py

@@ -3,6 +3,7 @@ Views that are only activated when the project is running in development mode.
 These views will NOT be shown on production: trying to access them will result
 in a 404 error.
 """
+import bleach
 from django.http import HttpResponseNotFound
 from django.template import TemplateDoesNotExist
 from django.utils.translation import ugettext as _
@@ -52,4 +53,4 @@ def show_reference_template(request, template):
 
         return render_to_response(template, context)
     except TemplateDoesNotExist:
-        return HttpResponseNotFound('Missing template {template}'.format(template=template))
+        return HttpResponseNotFound('Missing template {template}'.format(template=bleach.clean(template, strip=True)))