Fixes #5986: Ensure tipsy error details populated on sync status page, BZ965230.

On the sync status page, if an error occurred during sync (e.g. using a URL
that doesn't point to a real repo) the tipsy with error details would not contain
the information until the page was reloaded.
Merge pull request #4179 from ehelms/fixes-5986

Fixes #5986: Ensure tipsy error details populated on sync status page, BZ965230.