Cleanup postgresql-server on openSUSE

During database cleanup, delete postgresql-server package also on
openSUSE.

Change-Id: I4dff0ac6493ab9b9a8c6ed15b7cfcdb35264da27
Merge "Cleanup postgresql-server on openSUSE"
Merge commit 'refs/changes/83/86083/2' of git://gold.eng.hq.xensource.com/git/github/openstack-dev/devstack into tmpbranch