Cleanup postgresql-server on openSUSE

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

Change-Id: I4dff0ac6493ab9b9a8c6ed15b7cfcdb35264da27
diff --git a/lib/databases/postgresql b/lib/databases/postgresql
index 96a5947..b39984c 100644
--- a/lib/databases/postgresql
+++ b/lib/databases/postgresql
@@ -23,7 +23,7 @@
         # Get ruthless with mysql
         apt_get purge -y postgresql*
         return
-    elif is_fedora; then
+    elif is_fedora || is_suse; then
         uninstall_package postgresql-server
     else
         return