fix: exclude 'course_key' field from the django admin form on course_…

…action_state

common/djangoapps/course_action_state/admin.py

@@ -6,4 +6,16 @@
 
 from common.djangoapps.course_action_state.models import CourseRerunState
 
-admin.site.register(CourseRerunState)
+
+class CourseRerunStateAdmin(admin.ModelAdmin):
+
+    exclude = ["course_key"]
+
+    def get_queryset(self, request):
+        # For any query against this table, remove course_key field
+        # because that field might have bad data in it.
+        qs = CourseRerunState.objects.defer('course_key')
+        return qs
+
+
+admin.site.register(CourseRerunState, CourseRerunStateAdmin)