new blog posts always fail PR validation

[SethTisue]

seen at e.g. #872, and I recall seeing it on other similar pull requests

it's a chicken-and-egg problem. perhaps easily fixed? needs investigation

[lrytz]

While working on the compiler boostrapt scripts recently, I also saw http://pgp.mit.edu failing from time to time, then coming back.

[SethTisue]

While working on the compiler boostrapt scripts recently, I also saw http://pgp.mit.edu failing from time to time, then coming back

separate ticket on this: #881