tls-toolkit pkcs12 truststore 0 entries

When pkcs12 is used by the tls-toolkit, the resulting truststore has no entries when inspected by the keytool and the tls-toolkit certificate authority certificate is not trusted by NiFi.

This seems to be due to the Java pkcs12 provider not supporting certificate entries:
http://stackoverflow.com/questions/3614239/pkcs12-java-keystore-from-ca-and-user-certificate-in-java#answer-3614405

The Bouncy Castle provider does seem to support certificates but we may not want to explicitly use that provider from within NiFi.