Incorrect column pruning

[MaxGekk]

On the following file:

"1","DE","","Yes"
"5",",","",","
"3","SA","","No"
"10","abcd""efgh"" \ndef","",""

when I select the index 0, I would expect 1, 5, 3, 10 but got 1, 5, 10.

Here is the example which reproduces the issue:

    CsvParserSettings settings = new CsvParserSettings();
    CsvFormat format = settings.getFormat();
    format.setQuoteEscape('"');
    settings.selectIndexes(0);

    CsvParser parser = new CsvParser(settings);
    File initialFile = new File("test.csv");
    InputStream inputStream = new FileInputStream(initialFile);
    List<String[]> allLines = parser.parseAll(inputStream);

    int count = 0;
    for(String[] line : allLines){
      System.out.println("Line " + ++count);
      for(String element : line){
        System.out.println("\t" + element);
      }
      System.out.println();
    }

the output is:

Line 1
	1

Line 2
	5

Line 3
	10

but when I select at least 3 indexes (0, 1, 2) or remove settings.selectIndexes(0), the output is correct.

settings.selectIndexes(0, 1, 2);

Line 1
	1
	DE
	null

Line 2
	5
	,
	null

Line 3
	3
	SA
	null

Line 4
	10
	abcd"efgh" \ndef
	null

[MaxGekk]

We faced to the issue in Apache Spark since the column pruning feature is enabled by default in the CSV datasource. It would be nice to fix the issue in uniVocity instead of disabling the feature by default. cc @cloud-fan @HyukjinKwon