We have a liquibase command that looks something like this:

```sh
/liquibase/liquibase \
       --driver=org.postgresql.Driver \
       --changeLogFile="db.changelog-master.xml" \
       --url=<redacted> \
       --username=<redacted> \
       --password=<redacted> \
       update \
       -Dcoreschema="${core_schema}"
```

After upgrading the CLI from 4.3.3 to 4.4.0, it fails with the following error:

```
Unexpected argument(s): -Dcoreschema=public

For detailed help, try 'liquibase --help' or 'liquibase <command-name> --help'
```

Since the release notes state "this release should be 100% backwards compatible", I expect this is an oversight? Or is there a replacement for the `-Dproperty=value` syntax? I haven't found one looking through `--help` and the [property substitution docs](https://docs.liquibase.com/concepts/basic/changelog-property-substitution.html) at least.

The syntax can also still be found on https://docs.liquibase.com/tools-integrations/cli/home.html:

![image](https://user-images.githubusercontent.com/2620907/122090597-36d63400-ce08-11eb-92e8-d320cd5c5baa.png)


private final Map<String, String> legacyPositionalArguments;
    /**
     * Arguments that used to be global arguments but are now command-level
     */
    private final Set<String> legacyNoLongerGlobalArguments;
    /**
     * Arguments that used to be command arguments but are now global
     */
    private final Set<String> legacyNoLongerCommandArguments;
    private Level configuredLogLevel;
    private final CommandLine commandLine;
    private FileHandler fileHandler;
    private final ResourceBundle coreBundle = getBundle("liquibase/i18n/liquibase-core");
    /**
     * Pico's defaultFactory does a lot of reflection, checking for classes we know we don't have.
     * That is slow on older JVMs and impact initial startup time, so do our own factory for performance reasons.
     * It is easy to configure pico to it's default factory, when profiling check for `CommandLine$DefaultFactory` usage
     */
    private CommandLine.IFactory defaultFactory = new CommandLine.IFactory() {
        @Override
        public <K> K create(Class<K> cls) throws Exception {
            return cls.newInstance();
        }
    };
    public static void main(String[] args) {
        
        System.setProperty("org.fusesource.jansi.Ansi.disable", "true");
        final LiquibaseCommandLine cli = new LiquibaseCommandLine();