fix deprecation warning

Author: marschall

src/main/java/com/github/marschall/hibernate/batchsequencegenerator/BatchSequenceGenerator.java

@@ -3,6 +3,7 @@
 import java.io.Serializable;
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.math.RoundingMode;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -385,7 +386,7 @@ Serializable extractIdentifier(ResultSet resultSet) throws SQLException {
         if (resultSet.wasNull()) {
           throw new IdentifierGenerationException("sequence returned null");
         }
-        return bigDecimal.setScale(0, BigDecimal.ROUND_UNNECESSARY).toBigInteger();
+        return bigDecimal.setScale(0, RoundingMode.UNNECESSARY).toBigInteger();
       }
     },