sagews: Fix the exercise decorator, which was broken by a change in Sage. (reported by Dominique Laurain)
sagews: Fix the exercise decorator, which was broken by a change in Sage. (reported by Dominique Laurain)

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