Uploading config file does not update pwenc_secret file

Just re-encountered this while reinstalling.

Steps to repro:

1. Fresh install (In this case, 11.3 preview). I updated to the latest nightly at this point FreeNAS-11.3-MASTER-202001050957
2. Uploaded config file tar, which included database and pwenc_secret file.
3. System rebooted, did migrations and rebooted again.
4. Could not decrypt SSH Keypairs and other things.
5. Check /data and notice that pwenc_secret file is still from today and is different from the config save's copy.
6. Copied over the file from the config, instant access to the encrypted settings

I'm not sure, but this might be due to the upload routine simply trying to mv the file into place, which fails since there's already one in the destination? Not sure, the logs don't seem to be preserved from the upload.