Error: Your public key appears corrupted (no header found)

I'm getting this error when attempting to upload my public GPG key. I previously had the same key on keybase but it was expired.

This key appears freshly exported from GPG and looks something like

```
-----BEGIN PGP PUBLIC KEY BLOCK-----

mQINBFKmKTkBEADEwkkP4B2KFD5at2PwSsdfVZaASdlmylQ4ZF9AeQzz5dy2woy1
...
-----END PGP PUBLIC KEY BLOCK-----
```

If I export the private key it looks something like

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

lQdGBFK...

-----END PGP PRIVATE KEY BLOCK-----
```

I initially thought this was something similar to #184 or #399 but this is a working key that I've been using with GPG since 2013 so I'm pretty sure it's valid.

You can find the updated key I'm trying to use on mit key server - `E2804455` http://pgp.mit.edu/pks/lookup?search=E2804455&op=index

When I look at the key it appears to not be expired, am I missing something?

```
➜ gpg -v < ~/Downloads/Marshall\ Jones\ \(E2804455\)\ –\ Public.asc
gpg: WARNING: no command supplied. Trying to guess what you mean ...
pub rsa4096 2013-12-09 [SC] [expires: 2020-12-10]
50433C86AAD6968F3D288F98F439FD97E2804455
uid Marshall Jones
sig F439FD97E2804455 2013-12-09 [selfsig]
sig F439FD97E2804455 2013-12-09 [selfsig]
sig F439FD97E2804455 2017-06-22 [selfsig]
uid Marshall Jones👨
sig F439FD97E2804455 2013-12-09 [selfsig]
sig F439FD97E2804455 2017-06-22 [selfsig]
uid Marshall Jones👨
sig F439FD97E2804455 2013-12-09 [selfsig]
rev F439FD97E2804455 2017-06-22 [selfsig]
sig F439FD97E2804455 2017-06-22 [selfsig]
uid Marshall Jones👨
sig F439FD97E2804455 2015-04-30 [selfsig]
sig F439FD97E2804455 2017-06-22 [selfsig]
uid Marshall Jones
sig F439FD97E2804455 2016-06-07 [selfsig]
sig F439FD97E2804455 2017-06-22 [selfsig]
sub rsa4096 2013-12-09 [E] [expires: 2020-12-21]
sig F439FD97E2804455 2017-12-20 [keybind]
➜
```

Reproduce the public-key upload with the supplied ASCII-armored key, fingerprint E2804455, and the reported “no header found” error. Trace the upload validation that rejects the public key and compare its handling with the private-key example; done means a valid exported public key is accepted or the error identifies the actual formatting problem.

Written by the indexing model from the issue text.