Update docs after drop of commons-httpclient-3.1
Update docs after drop of commons-httpclient-3.1

git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1783600 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: e7bdf9bed9941170bd0b9ee79c58cab67bd8d4be
benbenw/jmeter,etnetera/jmeter,apache/jmeter,etnetera/jmeter,benbenw/jmeter,ham1/jmeter,apache/jmeter,apache/jmeter,ham1/jmeter,apache/jmeter,ham1/jmeter,ham1/jmeter,benbenw/jmeter,etnetera/jmeter,benbenw/jmeter,apache/jmeter,ham1/jmeter,etnetera/jmeter,etnetera/jmeter