GEODE-5820: upgrade jetty to fix jetty tests in java10

[jinmeiliao]

Co-authored-by: Patrick Rhomberg prhomberg@pivotal.io

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[PurelyApplied]

+1, but I might not mention the java version in the commit message? While that might have been our original motivation, staying up-to-date in our tools has inherent value.

I dunno. Could go either way, really. +1 in any case.

[jinmeiliao]

we can change it to java 9+