Delay copying of resolv.conf into the chroot until /etc exists.

With an unpopulated chroot dir, release building was failing because
the script was attempting to copy resolv.conf into a non-existent /etc
directory of the chroot.  Fix this by copying the file only after the
installworld has happened, which will create this directory.

Reviewed by:	gjb
Approved by:	rpaulo (mentor)

release/release.sh

@@ -162,12 +162,12 @@ if [ "x${NOPORTS}" = "x" ]; then
 	svn co ${SVNROOT}/${PORTBRANCH} ${CHROOTDIR}/usr/ports
 fi
 
-cp /etc/resolv.conf ${CHROOTDIR}/etc/resolv.conf
 cd ${CHROOTDIR}/usr/src
 make ${CHROOT_WMAKEFLAGS} buildworld
 make ${CHROOT_IMAKEFLAGS} installworld DESTDIR=${CHROOTDIR}
 make ${CHROOT_DMAKEFLAGS} distribution DESTDIR=${CHROOTDIR}
 mount -t devfs devfs ${CHROOTDIR}/dev
+cp /etc/resolv.conf ${CHROOTDIR}/etc/resolv.conf
 trap "umount ${CHROOTDIR}/dev" EXIT # Clean up devfs mount on exit
 
 build_doc_ports() {