Undefined index: file at /apps/files_sharing/lib/Activity/Providers/Downloads.php#123

[LukasReschke]

Multiple times in my log file:

{"reqId":"HYyknFXS6Hrd79\/8ppZZ","remoteAddr":"10.211.55.2","app":"PHP","message":"Undefined index: file at \/media\/psf\/nextcloud\/apps\/files_sharing\/lib\/Activity\/Providers\/Downloads.php#120","level":3,"time":"2016-11-22T17:48:01+00:00","method":"GET","url":"\/nextcloud\/index.php\/apps\/activity\/api\/v2\/activity\/all?format=json&previews=true&since=0","user":"test","version":"11.0.0.2"}

cc @nickvergessen