Fix name of RDMA configuration directive in standalone install

Author: vbwagner

doc/src/sgml/installation.sgml

@@ -805,7 +805,7 @@ su - postgres
         <para>
          Enable <literal>rsocket</literal> API support for remote direct memory access (<acronym>RDMA</acronym>).
          You must also set the
-      <![%standalone-include[listen-rdma-address]]>
+      <![%standalone-include[listen_rdma_addresses]]>
       <![%standalone-ignore[<xref linkend="listen-rdma-addresses">]]>
           variable for your server to enable <acronym>RDMA</acronym> connections via <literal>rsocket</literal>.
         </para>