Fix Multiple CA in ca.crt file

[leszko]

Before only the first CA Certificate was read from the ca.crt file, which made the discovery failing in case of multiple entries in ca.crt.

This PR is a follow-up of the IBM Cloud Pak certification process.

[kwart]

What do you think about renaming RestClient.withCaCertificate method to withCaCertificates?

There could be also a test related issue on IBM JDKs (if we support this runtime). IBM JDK has a sensitive X.509 parser, so the empty lines within ca.crt could cause some troubles.

Otherwise LGTM.

[leszko]

What do you think about renaming RestClient.withCaCertificate method to withCaCertificates?

Good idea, renamed!

There could be also a test related issue on IBM JDKs (if we support this runtime). IBM JDK has a sensitive X.509 parser, so the empty lines within ca.crt could cause some troubles.

I believe we don't have to test it using IBM JDK, because we don't publish any Docker image based on IBM JDK. Also, I believe that if ca.crt (generated by Kubernetes) would not be compatible with IBM JDK parser, then it won't be only the problem of Hazelcast, but a lot of other tools.

Otherwise LGTM.

Thanks for the review @kwart !!!