## Environment
**Liquibase Version**:
4.0.0 -> current (I'm testing on 4.2.2)

**Liquibase Integration & Version**: 
Java

**Liquibase Extension(s) & Version**: 
None

**Database Vendor & Version**:
ALL / not really relevant

**Operating System Type & Version**:
ALL / not really relevant

## Description
Regression of https://liquibase.jira.com/browse/CORE-3198, when merging 3.10 to 4.0 looks like this flag was accidentally wiped out.

## Steps To Reproduce
List the steps to reproduce the behavior.

1. Set property "liquibase.prefer.internal.xsd"
1. Disconnect internet, or open WireShark or similar tool
1. Run any XML changeset

## Actual Behavior
Running the changeset fails with

`Failed to read schema document 'http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-4.2.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>`

## Expected/Desired Behavior
It should use the XSD out of the jar

## Additional Context
Broken: ee233bd4c082f7e58de7ce5f7a2e6910a67f9f59

To fix add this code to the constructor of XMLChangeLogSAXParser (as in previous versions, eg: https://github.com/liquibase/liquibase/blob/a8b11044a571a11a7b904dfc7dce364fd0d49f37/liquibase-core/src/main/java/liquibase/parser/core/xml/XMLChangeLogSAXParser.java )
`
if (PREFER_INTERNAL_XSD) {
            InputStream xsdInputStream = XMLChangeLogSAXParser.class.getResourceAsStream(XSD_FILE);
            if (xsdInputStream != null) {
                try {
                    SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
                    Schema schema = schemaFactory.newSchema(new StreamSource(xsdInputStream));
                    saxParserFactory.setSchema(schema);
                    saxParserFactory.setValidating(false);
                } catch (SAXException e) {
                    LogService.getLog(XMLChangeLogSAXParser.class).warning("Could not load " + XSD_FILE + ", enabling parser validator", e);
                }
            }
        }
`


return changeLogFile.toLowerCase().endsWith("xml");
    }
    protected SAXParserFactory getSaxParserFactory() {
        return saxParserFactory;
    }
    @Override
    protected ParsedNode parseToNode(String physicalChangeLogLocation, ChangeLogParameters changeLogParameters, ResourceAccessor resourceAccessor) throws ChangeLogParseException {
        try (InputStream inputStream = resourceAccessor.openStream(null, physicalChangeLogLocation)) {
            SAXParser parser = saxParserFactory.newSAXParser();
            trySetSchemaLanguageProperty(parser);
            XMLReader xmlReader = parser.getXMLReader();
            LiquibaseEntityResolver resolver = new LiquibaseEntityResolver();
            xmlReader.setEntityResolver(resolver);
            xmlReader.setErrorHandler(new ErrorHandler() {
                @Override
                public void warning(SAXParseException exception) throws SAXException {
                    Scope.getCurrentScope().getLog(getClass()).warning(exception.getMessage());
                    throw exception;
                }
                @Override
                public void error(SAXParseException exception) throws SAXException {
                    Scope.getCurrentScope().getLog(getClass()).severe(exception.getMessage());
                    throw exception;
                }
                @Override
                public void fatalError(SAXParseException exception) throws SAXException {
                    Scope.getCurrentScope().getLog(getClass()).severe(exception.getMessage());
                    throw exception;
                }
            });