Add a line to standalone.conf to enable experimental JDK 11 support for ByteBuddy

Hibernate ORM relies on ByteBuddy as the default bytecode provider.

To support JDK 11, ByteBuddy needs to enable some experimental features and we need an environment variable set: {{ -Dnet.bytebuddy.experimental=true}}.

I discussed with James P. and we decided the best was to include a new line in standalone.conf.

PR to come.

Note: this is needed for WF 14.