Simplify db lookup for queries by id

app/jobs/background_functions.py

@@ -3,7 +3,7 @@ from app.models import Job
 
 def delete_job_(app, job_id):
     with app.app_context():
-        job = Job.query.filter_by(id=job_id).first()
+        job = Job.query.get(job_id)
         if job is None:
             raise Exception('Job {} not found!'.format(job_id))
         job.delete()