Fingerprint spec fix

While trying to deploy a Linux VM, I found out that the underlying documentation was using the XML element name `FingerPrint`, while the actual service expects the lowercased equivalent, `Fingerprint`.

Updating the spec and regenerating fixed this, I was able to successfully create a new VM afterwards.

Code similar to:

```
                    linuxConfigurationSet.SshSettings = new SshSettings
                    {
                        PublicKeys = new List<SshSettingPublicKey>
                        {
                            new SshSettingPublicKey
                            {
                                Fingerprint = fingerprint,
                                Path = "/home/" + username + "/.ssh/authorized_keys",
                            }
                        }
                    };
```

Previously I would get a server-side validation error message of "Fingerprint and Path in SSHPublicKey should not be null or empty."

Previous payload contained:

```
          <DisableSshPasswordAuthentication>true</DisableSshPasswordAuthentication>
          <SSH>
            <PublicKeys>
              <PublicKey>
                <FingerPrint>AD33C19650A70DA8D509B359B8316B2B04FB1551</FingerPrint>
                <Path>/home/jeffwilcox/.ssh/authorized_keys</Path>
              </PublicKey>
            </PublicKeys>
            <KeyPairs />
          </SSH>
        </ConfigurationSet>
```

After the fix candidate I have, the payload is:

```
          <DisableSshPasswordAuthentication>true</DisableSshPasswordAuthentication>
          <SSH>
            <PublicKeys>
              <PublicKey>
                <Fingerprint>AD33C19650A70DA8D509B359B8316B2B04FB1551</Fingerprint>
                <Path>/home/jeffwilcox/.ssh/authorized_keys</Path>
              </PublicKey>
            </PublicKeys>
            <KeyPairs />
          </SSH>
        </ConfigurationSet>
```