pgsql: Update catalog version for recent relfilenode patch, so

Log Message:
-----------
Update catalog version for recent relfilenode patch, so pg_migrator can
identify the new API.

Modified Files:
--------------
pgsql/src/include/catalog:
catversion.h (r1.567 -> r1.568)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.567&r2=1.568)