Remove default definition of log_file so can be provided via Java property
Remove default definition of log_file so can be provided via Java property

git-svn-id: https://svn.apache.org/repos/asf/jakarta/jmeter/branches/rel-2-1@351556 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: c0121e2c4e614fb0e1a5b3b1e2302cb5808a2dc9
apache/jmeter,etnetera/jmeter,ham1/jmeter,apache/jmeter,etnetera/jmeter,etnetera/jmeter,ham1/jmeter,benbenw/jmeter,ham1/jmeter,etnetera/jmeter,apache/jmeter,ham1/jmeter,benbenw/jmeter,apache/jmeter,apache/jmeter,ham1/jmeter,benbenw/jmeter,benbenw/jmeter,etnetera/jmeter