pgsql: Add a further customization to the SGML Emacs mode to prevent the

Log Message:
-----------
Add a further customization to the SGML Emacs mode to prevent the use of
tabs in the documentation source.

Modified Files:
--------------
pgsql/src/tools/editors:
emacs.samples (r1.3 -> r1.4)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/tools/editors/emacs.samples?r1=1.3&r2=1.4)