Add 9.1 release note link for synchronous replication.

bmomjian · bmomjian · commit 5c22c0eda145 · 2011-03-28T14:50:08.000-04:00
We already had links to the GUC variables that control it.
diff --git a/doc/src/sgml/release-9.1.sgml b/doc/src/sgml/release-9.1.sgml
@@ -646,7 +646,8 @@
 
      <listitem>
       <para>
-       Allow synchronous replication (Simon Riggs, Fujii Masao)
+       Allow <link linkend="synchronous-replication">synchronous
+       replication</link> (Simon Riggs, Fujii Masao)
       </para>
 
       <para>
