Catch exception when a renderer freaks out
Summary:
Had some cases where the Py-Notebook(?) renderer throws an exception in `can render`, blocking the entire page render.
"False" is probably the right answer if you crash here.
Test Plan: Loaded same file, saw some meta-data about the file.
Reviewers: O1 Blessed Committers, valerio.bozzolan
Reviewed By: O1 Blessed Committers, valerio.bozzolan
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Differential Revision: https://we.phorge.it/D25984