CHANGELOG entry for the whitelistable sandboxing change.

CHANGELOG.rst

@@ -5,11 +5,15 @@ These are notable changes in edx-platform.  This is a rolling list of changes,
 in roughly chronological order, most recent first.  Add your entries at or near
 the top.  Include a label indicating the component affected.
 
+
 Studio, LMS: Make ModelTypes more strict about their expected content (for
 instance, Boolean, Integer, String), but also allow them to hold either the
 typed value, or a String that can be converted to their typed value. For example,
 an Integer can contain 3 or '3'. This changed an update to the xblock library.
 
+LMS: Courses whose id matches a regex in the COURSES_WITH_UNSAFE_CODE Django
+setting now run entirely outside the Python sandbox.
+
 Blades: Video Alpha bug fix for speed changing to 1.0 in Firefox.
 
 Blades: Additional event tracking added to Video Alpha: fullscreen switch, show/hide