Log Message:
-----------
Fix typo in backup docs. Patch from Euler Taveira de Oliveira.
Modified Files:
--------------
pgsql/doc/src/sgml:
backup.sgml (r2.91 -> r2.92)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/backup.sgml.diff?r1=2.91&r2=2.92)