LUCENENET-339 : Fix for exception thrown by FilterCleaner
LUCENENET-339 : Fix for exception thrown by FilterCleaner

git-svn-id: b2dcba4c53c5fa0a86ccceee81d7e0ce197ae049@911185 13f79535-47bb-0310-9956-ffa450edef68

NightOwl888/lucenenet,laimis/lucenenet,jeme/lucenenet,jpsullivan/lucenenet,apache/lucenenet,jeme/lucenenet,laimis/lucenenet,mdissel/lucene.net,mdissel/lucene.net,zmaruo/lucenenet,apache/lucenenet,antiufo/lucenenet,jpsullivan/lucenenet,jeme/lucenenet,jeme/lucenenet,sisve/lucenenet,NightOwl888/lucenenet,antiufo/lucenenet,NightOwl888/lucenenet,sisve/lucenenet,NightOwl888/lucenenet,apache/lucenenet,zmaruo/lucenenet,apache/lucenenet