Fix postgresql_psql autorequire

It does not really make sense to require the "begin" anchor, the
`postgresql_psql` type communicating with the server, it makes more
sense to require the "end" anchor which mean that the server is running
and reachable.

lib/puppet/type/postgresql_psql.rb

@@ -135,7 +135,7 @@ def matches(value)
   end
 
   autorequire(:anchor) do
-    ["postgresql::server::service::begin::#{self[:instance]}"]
+    ["postgresql::server::service::end::#{self[:instance]}"]
   end
 
   autorequire(:service) do