Log Message:
-----------
Fix up grammar in variable description string.
Modified Files:
--------------
pgsql/src/backend/utils/misc:
guc.c (r1.290 -> r1.291)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c.diff?r1=1.290&r2=1.291)