(maint) accomodate old pgsql version We still support older OSes like redhat 5 which, by default, installs postgresql 8.1. This version does not support the CONNECT privilege, which is used to set up the grant tests. Fixing this completely is both out of scope and low priority given the age of 8.1, so this commit adds a bandaid to skip these tests if pgsql is below 8.4