preseed path for generated tgz doesn't match actual path

[Jason Hobbs]

This is maas 1.7.0~beta2+bzr2847-0ubuntu1~ppa1

When I try to boot a centos node, cloud-init/curtin tries to download the root-tgz from http://192.168.0.151/MAAS/static/images/centos/amd64/generic/centos65/generated/root-tgz, but it's really at http://192.168.0.151/MAAS/static/images/centos/amd64/generic/centos65/generated/tgz, so the installation fails.

Cloud-init v. 0.7.5 running 'modules:final' at Sat, 30 Aug 2014 22:14:44 +0000. Up 30.14 seconds.
--2014-08-30 22:14:47-- http://192.168.0.151/MAAS/static/images/centos/amd64/generic/centos65/generated/root-tgz
Connecting to 192.168.0.151:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2014-08-30 22:14:47 ERROR 404: Not Found.

gzip: stdin: unexpected end of file
tar: Child returned status 1
tar: Error is not recoverable: exiting now
Unexpected error while running command.
Command: ['sh', '-c', 'wget "$1" --progress=dot:mega -O - |tar -C "$2" -Sxpzf - --numeric-owner', '--', 'http://192.168.0.151/MAAS/static/images/centos/amd64/generic/centos65/generated/root-tgz', '/tmp/tmpzNbCXc/target']
Exit code: 2
Reason: -
Stdout: ''
Stderr: ''
Unexpected error while running command.
Command: ['curtin', 'extract']
Exit code: 3
Reason: -
Stdout: ''
Stderr: ''