doc: Fix typo in example query of SQL/JSON

Author: Erik Rijkers
Discussion: https://postgr.es/m/1219476687.20432.1617452918468@webmailclassic.xs4all.nl
Backpatch-through: 12

Author: michaelpq

doc/src/sgml/json.sgml

@@ -489,7 +489,7 @@ CREATE INDEX idxgintags ON api USING GIN ((jdoc -> 'tags'));
 SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @@ '$.tags[*] == "qui"';
 </programlisting>
 <programlisting>
-SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @@ '$.tags[*] ? (@ == "qui")';
+SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @? '$.tags[*] ? (@ == "qui")';
 </programlisting>
     GIN index extracts statements of following form out of
     <literal>jsonpath</literal>: <replaceable>accessors_chain</replaceable> = <replaceable>const</replaceable>.