Set `SslContextBuilder.endpointIdentificationAlgorithm` for Netty 4.2.x

[idelpivnitskiy]

Motivation:

In version 4.2.x, Netty introduced new API SslContextBuilder.endpointIdentificationAlgorithm(String) and flipped the default value to HTTPS.

Modifications:

• Detect presence of this new method and initialize it with the value from config.hostnameVerificationAlgorithm().
• Verify isOptionSupported method works as expected before initializing its MethodHandle.

Result:

Hostname verification algorithm is enabled/disabled as expected for ST users with Netty 4.2.x in the classpath.

[idelpivnitskiy]

Correct, I left that intentionally as a fallback for Netty 4.1.x