Cannot prove keys with zero creation time using "bash + GPG + cURL" method

To demonstrate the issue, here's a secret key with a creation time of zero (midnight, 1970-01-01):

```
-----BEGIN PGP PRIVATE KEY BLOCK-----

xVgEAAAAABYJKwYBBAHaRw8BAQdAmmCpo1rEqwekm2Za+K+Od/VMvoNXuTEPTb27
4c9d0sYAAP98oXD6UWUoO5LaXTNYhA6y7tf42l55sGOYHGopvb/uihHzzQh0ZXN0
IGtlecJhBBMWCAATBQIAAAAACRAk8R1uSjDJXgIbAwAAvxIBANb3ghasjJiyBi1y
xybXtYB1EUJSruJ92e+DtW6TmMbuAP9dps03o5OCaGNey8n/b0DWVE5AwAwzpj3A
TjPoD053BA==
=2TcC
-----END PGP PRIVATE KEY BLOCK-----
```

If I try to upload this key and prove it using the "bash + GPG + cURL" method, I get:

```
Error in your post
-------------------

Code: 501
Name: DB_INSERT_ERROR
Description: failed to insert into database
```

Here's the exact same key (identical key material) but with a creation time one second later. (The key ID only differs because the time is part of the key ID.)

```
-----BEGIN PGP PRIVATE KEY BLOCK-----

xVgEAAAAARYJKwYBBAHaRw8BAQdAmmCpo1rEqwekm2Za+K+Od/VMvoNXuTEPTb27
4c9d0sYAAP98oXD6UWUoO5LaXTNYhA6y7tf42l55sGOYHGopvb/uihHzzQh0ZXN0
IGtlecJhBBMWCAATBQIAAAABCRBBVGBMgS4sVgIbAwAAzH0A/AjwpFmjTl7qJ8oS
ajQwrpvzf/jnGgc1EXdaJ5IRn2JtAP9xKKr2y+FQRyUHVPKTZdXFxZwTdwWRLL9F
Hc9sjKd5CA==
=fJ+T
-----END PGP PRIVATE KEY BLOCK-----
```

I have no trouble proving this key using the same method. I *am* able to successfully prove the first key using the website method.

Start by reproducing the bash + GPG + cURL proof flow with the provided zero-creation-time key, then compare it with the one-second-later key and the website method. Trace the failed database insertion associated with Code 501/DB_INSERT_ERROR; done when the first key can be proved through the command-line method without that error.

Written by the indexing model from the issue text.