Better error message when viewing an embedded calendar as an unprivileged user

On our site's dashboard I have a calendar macro defined as:

{calendar:id=8f564b4b-afed-4ceb-b206-2e426f595648,a80c628d-5155-40bc-8a55-0874fb77bf71}

The result is something that looks like this:

After using the new features from TEAMCAL-102 to restrict view access of one of those calendars, users who don't have view rights to that calendar now see a huge warning on our site:

I believe the appropriate user experience would be to see no errors and no indication that there is a calendar that they do not have access to. I understand this has to be balanced with the requirement for editors to know if they fat-finger a calendar id in their macros when editing, and the error is probably useful then. But big red boxes on dashboards are worse.

Marking as critical because I believe this is a significant bug that will impact many users as they begin to utilize the new features from TEAMCAL-102.