Added the special setup instructions needed to run this program on m…

[Gopinathp]

…acOs

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[gjvanderheiden]

Don't recognize the instruction needed. Maybe I'm running a different JVM? Maybe change in, "if you get this error [...] try this [...]"?

[yfre]

works on my macosx and openjdk version "11.0.2" 2019-01-15 without this parameter
probably it would not hurt either, it just tell to use ipv4 instead of ipv6
probably comment like "in case you see that java hap uses ipv6 you can use following flag to force ipv4"