return thumbnail when successful rotation

files.py

@@ -513,6 +513,9 @@ def checkrotatejob():
     resp={}
     resp['finished']=False
     if job.pa_job_state == 'Completed':
+        id=[jex.value for jex in job.extra if jex.name == "id"][0]
+        e=Entry.query.join(File).filter(Entry.id==id).first()
+        resp['thumbnail']=e.file_details.thumbnail
         resp['finished']=True
     return resp