Search form IntegrityError.

[Rob Jackson]

https://app.getsentry.com/arcanaio/dotabank/group/21903441/

We really shouldn't let users face an error page if this throws IntegrityError - afterall that error is being thrown because the data is already in the database.

We can just wrap the db.commit() line in a try: except block, and redirect the user to the replays page if we catch the exception.