Don't show Download button for Multi-Site
Fix build-release grunt task

Occasionally the build-release grunt task fails with the error
"... has no method 'endsWith'"
Using the latest version of the download npm module fixes this.
Merge pull request #1724 from mlocati/fix-grunt-build-task

Fix build-release grunt task
Merge pull request #1722 from worldskills/fix-update-multi-site

Don't show download button for Multi-Site