remove unused import

Author: Vladimir Kotal

opengrok-indexer/src/main/java/org/opengrok/indexer/index/IndexDatabase.java

@@ -33,7 +33,6 @@
 import java.io.InputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
-import java.net.ConnectException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;