fix #4009 (hopefully!) -- course/clear_project_upgrades: invalid uuid='undefined'
fix #4009 (hopefully!) -- course/clear_project_upgrades: invalid uuid='undefined'

tscholl2/smc,tscholl2/smc,DrXyzzy/smc,sagemathinc/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc,sagemathinc/smc