External TLS certificate with Intermediate CA in server cert file fails

This was found while using Impala w/ KRPC with external PKI.

Take 2 certificate files: cert.pem and truststore.pem

cert.pem has 2 certificates in it:
A cert for that node (with CN="hostname", and signed by CN=CertToolkitIntCA)
And the intermediate CA cert (with CN=CertToolkitIntCA, and signed by CN=CertToolkitRootCA)

truststore.pem has 1 certificate in it:
A cert which is the root CA (with CN=CertToolkitRootCA, self-signed)

This format of certificates works with Impala on Thrift but it doesn't work with KRPC.

Workaround for this issue w/ KRPC turned on:
If we move the second certificate from cert.pem (CN=CertToolkitIntCA) into truststore.pem, then this seems to work.

Also TODO: Add a test case that has multiple intermediate CAs. Right now we're testing with only one intermediate CA.