Update Apache Cassandra download link
Update Apache Cassandra download link

New link now points to Apache archive, since mirrors only host last
two stable releases. And since there is one release per month, out
stable releases of chef recipes would be broken in two months time.

Change-Id: I48d933ec8c5e2b67727974d6fc46bdfd64d8ed28

dice-project/DICE-Chef-Repository,dice-project/DICE-Chef-Repository,dice-project/DICE-Chef-Repository,dice-project/DICE-Chef-Repository