Suppress duplicate-index-entry warning introduced by previous commit.

We don't need two index entries for lo_create pointing at the same section.
It's a bit pedantic for the toolchain to warn about this, but warn it does.

doc/src/sgml/lobj.sgml

@@ -600,7 +600,7 @@ int lo_unlink(PGconn *conn, Oid lobjId);
    client-side functions are simply interfaces to the equivalent server-side
    functions.  The ones just as convenient to call via SQL commands are
    <function>lo_creat</function><indexterm><primary>lo_creat</></>,
-   <function>lo_create</function><indexterm><primary>lo_create</></>,
+   <function>lo_create</function>,
    <function>lo_unlink</function><indexterm><primary>lo_unlink</></>,
    <function>lo_import</function><indexterm><primary>lo_import</></>, and
    <function>lo_export</function><indexterm><primary>lo_export</></>.