Remove "reliably" from chr(0) doc mention.

doc/src/sgml/func.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.421 2008/03/03 17:11:13 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.422 2008/03/03 18:09:02 momjian Exp $ -->
 
  <chapter id="functions">
   <title>Functions and Operators</title>
@@ -1341,7 +1341,7 @@
         argument is treated as a Unicode code point. For other multibyte
         encodings the argument must designate a strictly
         <acronym>ASCII</acronym> character.  The NULL (0) character is not
-        allowed because text data types cannot reliably store such bytes.
+        allowed because text data types cannot store such bytes.
        </entry>
        <entry><literal>chr(65)</literal></entry>
        <entry><literal>A</literal></entry>