KNL-1264 Fixed Site Archive import causes NPE in BaseSite.set



git-svn-id: https://source.sakaiproject.org/svn/kernel@310217 66ffb92e-73f9-0310-93c1-f5514f145a0a
KNL-1264 merge 310217 to 10.x

git-svn-id: https://source.sakaiproject.org/svn/kernel@310222 66ffb92e-73f9-0310-93c1-f5514f145a0a