Fix typo in transam.h for OIDs assigned by genbki.pl

The actual range of reserved OIDs in this case is [11000,11999] and not
[11000,12000].

Author: John Naylor
Discussion: https://postgr.es/m/CAJVSVGV5StmK-inxbmrf0nLbBGeaAKnjnqxXmk+4ufeav8JMSA@mail.gmail.com

src/include/access/transam.h

@@ -74,7 +74,7 @@
  *		OIDs 1-9999 are reserved for manual assignment (see .dat files in
  *		src/include/catalog/), with 9000-9999 tentatively reserved for forks.
  *
- *		OIDs 10000-12000 are reserved for assignment by genbki.pl, when the
+ *		OIDs 10000-11999 are reserved for assignment by genbki.pl, when the
  *		.dat files in src/include/catalog/ do not specify oids.
  *
  *		OIDS 12000-16383 are reserved for assignment during initdb