title: Node openpgp error when encrypting: Could not find valid key packet for encryption in key
body: <p>I have a error when trying to encrypt a string with a pgp public key:
  'Could not find valid key packet for encryption in key 9ae788ff8eec0b31'</p>
  
  <p>This error doesn't appear with every key but with most of them. Here one of the keys that errors:</p>
  
  <pre><code>-----BEGIN PGP PUBLIC KEY BLOCK-----
  Version: BCPG v1.43
  
  mI0EXQJU0gEEAKZKsTmlR71mPgzQR6hyGJXR4tuoH/RgJPnZGCKPlJqCj8GCvlTa
  Jqy5gUZQJItwS4ssFU56+fI1a47oe08covHWgLAsGRWCxsD/oneFhddPhhZkHOui
  s1CW3CNDQ8hhl/DykhUoegKCmvNDzRVsD4y7ueLkzAisu3MH3ShQWDB/ABEBAAG0
  CUxJTlhPIFNBU4icBBABAgAGBQJdAlTSAAoJEPa8OTh7Vcnz4kID/0KL7RBA5Z83
  WuirfaVXF+Kqi4QXQO4EBUUknSbO+igRSJ/MLV4NROuhn2AZ3YWXK9B8rLsaZy9Q
  49/rr1lPn648Wq2lAoN7uLwtycspFQscjLT76hDMnoOvJGzjrpi+xC7n0W7ggLRN
  TkCUB8b+OBvwPhptny8kS6DASwew0Fp7
  =2Sis
  -----END PGP PUBLIC KEY BLOCK-----
  </code></pre>
  
  <p>Here is the function im using to encrypt</p>
  
  <pre><code>    const openpgp = require('openpgp')
      async function pgpEncrypt(pubkey, message) {
          await openpgp.initWorker({ path: 'openpgp.worker.js' })
          const options = {
              message: await openpgp.message.fromText(message), // input as Message object
              publicKeys: (await openpgp.key.readArmored(pubkey)).keys, // for encryption
              armor: false
          }
          const cipherText = await openpgp.encrypt(options)
          return cipherText.data
      }
  </code></pre>
  
  <p>What's wrong with this? how can i ensure the key works with this library? </p>