relnotes: mention non-exclusive backup mode was deprecated

bmomjian · bmomjian · commit 6bfecf33f6ed · 2022-05-11T22:46:56.000-04:00
Reported-by: Ian Lawrence Barwick Discussion: https://postgr.es/m/CAB8KJ=j9VhsFXuN+xv5qzxQV7gj-6TKqqwVLSgz5zU7F8nHCYw@mail.gmail.com
diff --git a/doc/src/sgml/release-15.sgml b/doc/src/sgml/release-15.sgml
@@ -84,7 +84,7 @@ Author: Stephen Frost <sfrost@snowman.net>
 
 <listitem>
 <para>
-Remove exclusive backup mode (David Steele, Nathan Bossart)
+Remove long-deprecated exclusive backup mode (David Steele, Nathan Bossart)
 </para>
 
 <para>
