PR with empty commit causes problems

[zcorpan]

We tried enabling Pull Panda for the web-platform-tests org, but it appears that a PR with an empty commit causes problems for Pull Panda Analytics.

In the "PR merge time" page, there is only one data point (that PR), among all repos for the past 24 weeks. Similarly for the other pages; a lot of data is missing.

[zcorpan]

I have excluded the wpt-actions-tests repo, but the problem seems to persist because the wpt repo (the most interesting one in our case) also has at least one PR with an empty commit.