DOC: fixed basebackup example in multimaster docs

Author: Liudmila Mantrova

doc/src/sgml/multimaster.sgml

@@ -363,7 +363,7 @@
               <application>pg_basebackup</application> on behalf of this user.
               Run the following command on each node you are going to add:
             <programlisting>
-pg_basebackup -D <replaceable>datadir</> -h node1 -U myuser mydb
+pg_basebackup -D <replaceable>datadir</> -h node1 -U myuser
 </programlisting>
 where <replaceable>datadir</> is the directory containing the database cluster. This directory is specified at the cluster initialization stage, or set in the <envar>PGDATA</envar> environment variable.
 You can also use any other DBMS user with superuser rights instead of <literal>myuser</literal> to perform this task.