[appserver-io/appserver] Problems setting base dir for wrong configuration sequence

[wick-ed]

We run into problems if the appserver.xml file gets configured in a certain, but XML wise valid, way.
The src/server.php script seems to have problems picking out the correct params element to add the base directory param to.

Re-testable by placing e.g. following logger configuration in front of the first params element:

<loggers>
    <logger channelName="system" name="System" type="\AppserverIo\Logger\Logger">
        <handlers>
            <handler type="\AppserverIo\Logger\Handlers\CustomFileHandler">
                <formatter type="\AppserverIo\Logger\Formatters\StandardFormatter"/>
                <params>
                    <param name="logFile" type="string">var/log/appserver-errors.log</param>
                    <param name="logLevel" type="string">debug</param>
                </params>
            </handler>
        </handlers>
    </logger>
</loggers>