Switch to new style map.jinja

Move this formula to the new style map.jinja. Still need to sort out RedHat
handling, but it's not any worse than it was before (i.e. horribly broken)

postgres/client.sls

@@ -1,6 +1,6 @@
 {% from "postgres/map.jinja" import postgres with context %}
 
-{% if salt['pillar.get']('postgres:use_upstream_repo') %}
+{% if postgres.use_upstream_repo %}
 include:
   - postgres.upstream
 {% endif %}
@@ -8,7 +8,7 @@ include:
 install-postgresql-client:
   pkg.installed:
     - name: {{ postgres.pkg_client }}
-    - refresh: {{ salt['pillar.get']('postgres:use_upstream_repo', False) }}
+    - refresh: {{ postgres.use_upstream_repo }}
 
 {% if postgres.pkg_libpq_dev != False %}
 install-postgres-libpq-dev: