Github alert only shows whitelisted labels openscholar/openscholar#3171

Set `github_integration_label_whitelist` to a comma separated list of github labels.  Only these labels will appear on the alert page.  It was looking cluttered.  By default it's empty so no labels will appear.
Missed file in earlier ocmmit openscholar/openscholar#3171

Forgot commit -a doesn't add new files.