Ensure that admin pages load on first try

[markmhendrickson]

Often sporadically admin pages don't load on first try, instead showing the following message:

First reported by @GinaAbrams

Notes from @hstove:

Update caching logic on app.co to allow running on multiple VMs, instead of just 1. Currently, app.co will occasionally not load (and then work on the next try) due to this issue.