## Environment
**Liquibase Version**: 4.2.1

**Liquibase Integration & Version**: maven

**Liquibase Extension(s) & Version**: 

spring boot 2.4.0
		<liquibase-hibernate5.version>4.1.1</liquibase-hibernate5.version>
		<validation-api.version>2.0.1.Final</validation-api.version>

**Database Vendor & Version**: h2

**Operating System Type & Version**: debian buster

## Description
When running mvn liquibase:diff the command fails with a NPE.

## Steps To Reproduce
[pom.txt](https://github.com/liquibase/liquibase/files/5660918/pom.txt)

Run mvn liquibase:diff

The changelog has no changes in it, liquibase:update runs smoothly.

## Actual Behavior
[logs.txt](https://github.com/liquibase/liquibase/files/5660924/logs.txt)

## Expected/Desired Behavior
A diff file was created…

## Screenshots (if appropriate)
If applicable, add screenshots to help explain your problem.

## Additional Context
Add any other context about the problem here.



┆Issue is synchronized with this [Jira Bug](https://datical.atlassian.net/browse/LB-1013) by [Unito](https://www.unito.io)
┆fixVersions: Liquibase 4.2.2

package liquibase.database.core;
import liquibase.database.DatabaseConnection;
import liquibase.database.jvm.JdbcConnection;
import liquibase.exception.DatabaseException;
import liquibase.util.JdbcUtils;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class CockroachDatabase extends PostgresDatabase {
    public CockroachDatabase() {
        super.setCurrentDateTimeFunction("NOW()");
    }
    @Override
    public int getPriority() {
        return super.getPriority() + 5;
    }
    @Override
    public String getShortName() {
        return "cockroachdb";
    }
    @Override
    protected String getDefaultDatabaseProductName() {
        return "CockroachDB";
    }
    @Override
    public boolean isCorrectDatabaseImplementation(DatabaseConnection conn) throws DatabaseException {
        if (conn instanceof JdbcConnection) {