Go back to using ifopen, first closing all interfaces.  What was wrong was the call to the default.ipxe.  When using ifopen, nothings been initialized and you need to specify the url to use (tftp://, http://) to get the default file.  This actually could allow us to dynamically generate the default.ipxe file using information from the http, but for now we'll keep things as it is.

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2770 71f96598-fa45-0410-b640-bcd6f8691b32