Unlock log file while running

Should prevent the following messages:
[2013-01-27 15:37:34,591] ERROR com.google.gerrit.pgm.util.LogFileCompressor : Cannot compress C:\Projects\gerrit\logs\gerrit_service_log
java.io.IOException: Cannot rename C:\Projects\gerrit\logs\.tmp.gerrit_service_log to C:\Projects\gerrit\logs\gerrit_service_log.gz
	at com.google.gerrit.pgm.util.LogFileCompressor.compress(LogFileCompressor.java:139)
	at com.google.gerrit.pgm.util.LogFileCompressor.run(LogFileCompressor.java:92)
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
	at java.util.concurrent.FutureTask$Sync.innerRunAndReset(Unknown Source)
	at java.util.concurrent.FutureTask.runAndReset(Unknown Source)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
	at com.google.gerrit.server.git.WorkQueue$Task.run(WorkQueue.java:337)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)