pgsql-server: Fix broken parsing of CREATE TABLE AS (looks like a

Log Message:
-----------
Fix broken parsing of CREATE TABLE AS (looks like a mis-sync with main
parser).

Modified Files:
--------------
pgsql-server/src/interfaces/ecpg/preproc:
preproc.y (r1.293 -> r1.294)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/preproc/preproc.y.diff?r1=1.293&r2=1.294)