If fetch of comments fails return an empty list.
If fetch of comments fails return an empty list.

This call to GH may not fail much in the real dev instance, but
it could time out. I'm getting it because I don't have my testing
instance configured and registered. This change would allow me to
run an incompletely configured instance and have some functionality.
Without this, I was getting 500's from any page load.

OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree