Unlock index when starting OpenMRS

org.apache.lucene.store.LockObtainFailedException: Lock obtain timed out: SimpleFSLock@/usr/share/tomcat7/.OpenMRS/lucene/indexes/org.openmrs.ConceptDatatype/write.lock
	at org.apache.lucene.store.Lock.obtain(Lock.java:84)
	at org.apache.lucene.index.IndexWriter.<init>(IndexWriter.java:1097)
	at org.hibernate.search.backend.Workspace.createNewIndexWriter(Workspace.java:202)
	at org.hibernate.search.backend.Workspace.getIndexWriter(Workspace.java:175)
	at org.hibernate.search.backend.Workspace.getIndexWriter(Workspace.java:210)
	at org.hibernate.search.backend.impl.batchlucene.DirectoryProviderWorkspace.doWorkInSync(DirectoryProviderWorkspace.java:96)
	at org.hibernate.search.backend.impl.batchlucene.LuceneBatchBackend$SyncBatchPerDirectoryWorkProcessor.addWorkToDpProcessor(LuceneBatchBackend.java:139)
	at org.hibernate.search.backend.impl.lucene.DpSelectionVisitor$PurgeAllSelectionDelegate.addAsPayLoadsToQueue(DpSelectionVisitor.java:119)
	at org.hibernate.search.backend.impl.batchlucene.LuceneBatchBackend.sendWorkToShards(LuceneBatchBackend.java:119)
	at org.hibernate.search.backend.impl.batchlucene.LuceneBatchBackend.doWorkInSync(LuceneBatchBackend.java:80)
	at org.hibernate.search.batchindexing.BatchCoordinator.beforeBatch(BatchCoordinator.java:153)
	at org.hibernate.search.batchindexing.BatchCoordinator.run(BatchCoordinator.java:96)
	at org.hibernate.search.impl.MassIndexerImpl.startAndWait(MassIndexerImpl.java:203)
	at org.openmrs.api.db.hibernate.HibernateContextDAO.updateSearchIndex(HibernateContextDAO.java:471)
	at org.openmrs.api.db.hibernate.HibernateContextDAO.setupSearchIndex(HibernateContextDAO.java:463)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:616)
	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:196)
	at $Proxy511.setupSearchIndex(Unknown Source)
	at org.openmrs.api.context.Context.startup(Context.java:830)
	at org.openmrs.web.filter.initialization.InitializationFilter$InitializationCompletion$1.run(InitializationFilter.java:1563)
	at java.lang.Thread.run(Thread.java:679)