Update spec/acceptance/server_instance_spec.rb

Co-authored-by: Ewoud Kohl van Wijngaarden <ewoud@kohlvanwijngaarden.nl>

Author: bastelfreak

spec/acceptance/server_instance_spec.rb

@@ -3,7 +3,7 @@
 # run a test task
 require 'spec_helper_acceptance'
 
-describe 'postgresql instance test1', if: os[:family] == 'redhat' && os[:release].split.first.to_i >= 8 do
+describe 'postgresql instance test1', if: os[:family] == 'redhat' && !os[:release].start_with?('7') do
   pp = <<-MANIFEST
   # set global defaults
   class { 'postgresql::globals':