+ close cleanly the writabledatabse at the end of the indexing process

src/common/kiwix/xapianIndexer.cpp

@@ -92,6 +92,7 @@ namespace kiwix {
   void XapianIndexer::indexingPostlude() {
     this->flush();
     this->writableDatabase.commit_transaction();
+    this->writableDatabase.close();
 
     // commit is not available is old version of xapian and seems not mandatory there
     // this->writableDatabase.commit();