ixp4xx-2.6: Removed the network config override file, cause we agreed that...

ixp4xx-2.6: Removed the network config override file, cause we agreed that ixp4xx images should behave like all other openwrt images. So ixp4xx images are static 192.168.1.1 on lan now instead of dhcp.

SVN-Revision: 7991