json docs fix jsonb_path_exists_tz again

[Erik Rijkers]

In funcs.sgml, the value fed into jsonb_path_exists_tz was wrong; fixed 
as attached.
(was inadvertently reverted with the big JSON revert)
Erik Rijkers--- doc/src/sgml/func.sgml.orig	2022-09-02 16:16:21.406405542 +0200
+++ doc/src/sgml/func.sgml	2022-09-02 16:17:41.751838806 +0200
@@ -16533,7 +16533,7 @@
         comparisons.
        </para>
        <para>
-        <literal>jsonb_path_exists_tz('["2015-08-01 12:00:00 -05"]', '$[*] ? (@.datetime() &lt; "2015-08-02".datetime())')</literal>
+        <literal>jsonb_path_exists_tz('["2015-08-01 12:00:00-05"]', '$[*] ? (@.datetime() &lt; "2015-08-02".datetime())')</literal>
         <returnvalue>t</returnvalue>
        </para></entry>
       </row>