Doc: fix obsolete info about allowed range of TZ offsets in timetz.

We've allowed UTC offsets up to +/- 15:59 since commit cd0ff9c0f, but
that commit forgot to fix the documentation about timetz.

Per bug #16571 from osdba.

Discussion: https://postgr.es/m/16571-eb7501598de78c8a@postgresql.org

doc/src/sgml/datatype.sgml

@@ -1727,8 +1727,9 @@ SELECT 'abc \153\154\155 \052\251\124'::bytea;
         <entry><type>time [ (<replaceable>p</replaceable>) ] with time zone</type></entry>
         <entry>12 bytes</entry>
         <entry>time of day (no date), with time zone</entry>
-        <entry>00:00:00+1459</entry>
-        <entry>24:00:00-1459</entry>
+        <!-- see MAX_TZDISP_HOUR in datatype/timestamp.h -->
+        <entry>00:00:00+1559</entry>
+        <entry>24:00:00-1559</entry>
         <entry>1 microsecond</entry>
        </row>
        <row>