install common packages (and hence create nova user) before trying to create a config file owned by the nova user

this was causing chef runs under folsom to fail.

The nova-rsyslog tries to create a config file owned by the nova user, but the recipe was getting called before any nova packages were installed.  Hence no nova user yet existed, and the run failed.

By ensureing we only include the rsyslog recipe after the common packages are installed, we make sure the nova user gets created first.