webapp/help: fix julia link
webapp/help: fix julia link

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