fix 6.2.8 input var ref (#99)

Author: Matthew OBrien

.gitignore

@@ -4,3 +4,4 @@ attrs.yml
 Gemfile.lock
 inputs.yml
 vendor
+.DS_Store

controls/6.02-db.rb

@@ -21,6 +21,7 @@
 log_min_error_statement = input('log_min_error_statement')
 log_error_verbosity = input('log_error_verbosity')
 log_statement = input('log_statement')
+log_hostname = input('log_hostname')
 control_id = '6.2'
 control_abbrev = 'db'