pgsql: Fix array_dims() example to be consistent with the data

Log Message:
-----------
Fix array_dims() example to be consistent with the data previously shown.
Christian Rossow

Modified Files:
--------------
pgsql/doc/src/sgml:
array.sgml (r1.61 -> r1.62)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/array.sgml.diff?r1=1.61&r2=1.62)