bugfix: now loading value of hold_time column in List table

src/main/java/de/srsoftware/widerhall/Util.java

@@ -16,6 +16,8 @@ import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.sql.ResultSet;
+import java.sql.SQLException;
 import java.util.Map;
 import java.util.stream.Collectors;
 
@@ -162,4 +164,9 @@ public class Util {
     public static String dropEmail(String tx) {
         return tx.replaceAll( "[.\\-\\w]+@[.\\-\\w]+", "[email_removed]");
     }
+
+    public static <T> T getNullable(ResultSet rs, String colName) throws SQLException {
+        final T val = (T) rs.getObject(colName);
+        return rs.wasNull() ? null : val;
+    }
 }