Handle the STRICT host name verifier explicitly (CodeQL java/missing-case-in-switch)

[vharseko]

Summary

Resolves the java/missing-case-in-switch alert in AsyncHttpClientProvider
(the switch had no case for HostnameVerifier.STRICT).

The switch pre-initialised the verifier and only overrode it for ALLOW_ALL:

HostnameVerifier verifier = new DefaultHostnameVerifier();
switch (options.get(OPTION_HOSTNAME_VERIFIER)) {
case ALLOW_ALL:
    verifier = NoopHostnameVerifier.INSTANCE;
    break;
}

STRICT therefore fell through and kept the default DefaultHostnameVerifier
(the correct behaviour), but the switch covered only one of the two enum values.

Fix

Add a default branch that assigns DefaultHostnameVerifier, matching the shape
already used by the sibling SyncHttpClientProvider:

final HostnameVerifier verifier;
switch (options.get(OPTION_HOSTNAME_VERIFIER)) {
case ALLOW_ALL:
    verifier = NoopHostnameVerifier.INSTANCE;
    break;
default:
    verifier = new DefaultHostnameVerifier();
    break;
}

Behaviour is unchanged (STRICT still maps to DefaultHostnameVerifier); the
switch now covers every value and the two providers are consistent.

Testing

mvn -o -pl commons/http-framework/client-apache-async compile — BUILD SUCCESS.