Changed default release number; 2.0.9-2 is not present in Debian nor in ...

Changed default release number; 2.0.9-2 is not present in Debian nor RHEL repo.

As of the 26th of August, 2.0.9-2 is not yet available in the official Datastax repositories at:
- http://rpm.datastax.com/community/noarch/
- http://debian.datastax.com/community/pool/

Release 2 might soon follow, but the current state of the master branch is not deployable in its current state without customizing the parameter.