Add a note about the usage of variables in 'Random Variable'. Bugzilla Id: 61318
Add a note about the usage of variables in 'Random Variable'. Bugzilla Id: 61318

git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1802524 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: 82b9921c42f20fe553e8732eaec52595ae1e47bb
apache/jmeter,ham1/jmeter,apache/jmeter,etnetera/jmeter,etnetera/jmeter,benbenw/jmeter,apache/jmeter,ham1/jmeter,ham1/jmeter,benbenw/jmeter,benbenw/jmeter,etnetera/jmeter,ham1/jmeter,benbenw/jmeter,apache/jmeter,ham1/jmeter,apache/jmeter,etnetera/jmeter,etnetera/jmeter