Upgrade to latest Lucene.

This includes some security fixes.

pom.xml

@@ -18,7 +18,7 @@
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<java.version>1.8</java.version>
-		<lucene.version>5.5.2</lucene.version>
+		<lucene.version>7.5.0</lucene.version>
 	</properties>
 
 	<dependencies>

src/main/java/org/ihtsdo/otf/sqs/service/SnomedQueryService.java

@@ -188,7 +188,7 @@ private ConceptIdResults getConceptIdResults(Query query, int offset, int limit)
 			final int fetchLimit = limit == -1 ? Integer.MAX_VALUE : limit + offset;
 			final TopDocs topDocs = indexSearcher.search(query, fetchLimit);
 			final ScoreDoc[] scoreDocs = topDocs.scoreDocs;
-			int total = topDocs.totalHits;
+			int total = (int) topDocs.totalHits;
 			List<Long> conceptIds = new LongArrayList();
 			for (int a = offset; a < scoreDocs.length; a++) {
 				String conceptId = getConceptId(scoreDocs[a]);
@@ -209,7 +209,7 @@ private ConceptResults getConceptResults(Query query, int offset, int limit) thr
 					new SortedNumericSortField(ConceptFieldNames.FSN_LENGTH, SortField.Type.INT)));
 
 			final ScoreDoc[] scoreDocs = topDocs.scoreDocs;
-			int total = topDocs.totalHits;
+			int total = (int) topDocs.totalHits;
 			List<ConceptResult> concepts = new ArrayList<>();
 			Map<String, ConceptResult> conceptsMap = new HashMap<>();
 			for (int a = offset; a < scoreDocs.length; a++) {