Update exp_updated_at only when exp changed.
Update exp_updated_at only when exp changed.

allenwq/coursemology.org,nnamon/coursemology.org,nnamon/coursemology.org,dariusf/coursemology.org,allenwq/coursemology.org,dariusf/coursemology.org,Coursemology/coursemology.org,allenwq/coursemology.org,nnamon/coursemology.org,Coursemology/coursemology.org,dariusf/coursemology.org,nnamon/coursemology.org,Coursemology/coursemology.org,Coursemology/coursemology.org,dariusf/coursemology.org,allenwq/coursemology.org,allenwq/coursemology.org,dariusf/coursemology.org,Coursemology/coursemology.org,nnamon/coursemology.org