[VIM] Spelling mistake in CVE-2008-4070 (minor)

[Steven M. Christey]

On Tue, 28 Oct 2008, Noam Rathaus wrote:

> In here:
> http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2008-4070
>
> Cancelling is spelled badly written as canceling

This was a direct quote from the Mozilla advisory, so we typically don't
try to change those.

- Steve