upgrading i386 to am64

[Sarton O'Brien <bsd-xen%roguewrt.org@localhost>]

When upgrading from i386 to amd64, upon first boot an error is thrown 
saying ldconfig is still an i386 binary:

eval: Cannot execute ELF binary /sbin/ldconfig

Copying ldconfig from /rescue to /sbin works but guessing there is 
something missing from the 'build.sh release' as it doesn't appear to be 
in the set? Just thought I'd mention it incase it was an oversight.

Sarton