ubox: update to git head

	- discard vfat labels with only spaces
	- support using swap files
	- support extroot when required kmods and block-mount are installed on jffs2

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37551 3c298f89-4303-0410-b956-a3cf2f4a3e73