Move 'ddl' right after 'none' in postgresql.conf. It used to be between

'mod' and 'all', which is not the right order.  SGML documentation order
was correct. Report from Chander Ganesan.

src/backend/utils/misc/postgresql.conf.sample

@@ -328,7 +328,7 @@
 					#        processes
 					#   %% = '%'
 					# e.g. '<%u%%%d> '
-#log_statement = 'none'			# none, mod, ddl, all
+#log_statement = 'none'			# none, ddl, mod, all
 #log_hostname = off