Avoid failing if empty settings file found (#1467)
Avoid failing if empty settings file found (#1467)

If a user settings or app settings file is found but empty, the JSON.parse will fail, since empty string isn't valid JSON.

* avoid failing if empty settings file found

* use const instead of var

googledatalab/datalab,yebrahim/datalab,googledatalab/datalab,craigcitro/datalab,googledatalab/datalab,googledatalab/datalab,craigcitro/datalab,craigcitro/datalab,yebrahim/datalab,parthea/datalab,craigcitro/datalab,parthea/datalab,googledatalab/datalab,craigcitro/datalab,parthea/datalab,parthea/datalab,yebrahim/datalab,parthea/datalab,yebrahim/datalab,parthea/datalab,googledatalab/datalab,yebrahim/datalab