Change release description

http://drupal.org/node/927058
The release description for the 7.x-2.x-dev release is outdated, and does not make sense at all..

"Please do not use this release but rather check out from CVS directly"
the dev releases are created regularly, the checkout is the "same" as the packaged release, so it is pointless to ask people to check out from the version control system (cvs or git)..