Yes, that repo is currently broken IIRC. Try here instead 
EDIT: Sorry, misread you. That’s for SpongeForge, I don’t think anything similar currently exists for SpongeVanilla. However, here’s a direct link to use in the mean time: Repository - Nexus Repository Manager
@blood @Zidane @Owexz: Is there a new repo for SpongeVanilla as well?