Mention need for --no-inc-recursive in rsync command

Since rsync 3.0.0 (released in 2008), the default way to enumerate
changes was changed in a way that makes it less likely that the hardlink
sync mode works. Since the whole point of the documented procedure is
for the hardlinks to work, change our docs to suggest using the
backwards compatibility switch.

doc/src/sgml/ref/pgupgrade.sgml

@@ -492,7 +492,7 @@ pg_upgrade.exe
        server:
 
 <programlisting>
-rsync --archive --delete --hard-links --size-only old_pgdata new_pgdata remote_dir
+rsync --archive --delete --hard-links --size-only --no-inc-recursive old_pgdata new_pgdata remote_dir
 </programlisting>
 
        where <option>old_pgdata</> and <option>new_pgdata</> are relative
@@ -504,7 +504,7 @@ rsync --archive --delete --hard-links --size-only old_pgdata new_pgdata remote_d
        remote directory, e.g.
 
 <programlisting>
-rsync --archive --delete --hard-links --size-only /opt/PostgreSQL/9.5/data \
+rsync --archive --delete --hard-links --size-only --no-inc-recursive /opt/PostgreSQL/9.5/data \
       /opt/PostgreSQL/9.6/data standby.example.com:/opt/PostgreSQL
 </programlisting>
 
@@ -534,7 +534,7 @@ rsync --archive --delete --hard-links --size-only /opt/PostgreSQL/9.5/data \
        <application>rsync</> command for each tablespace directory, e.g.:
 
 <programlisting>
-rsync --archive --delete --hard-links --size-only /vol1/pg_tblsp/PG_9.5_201510051 \
+rsync --archive --delete --hard-links --size-only --no-inc-recursive /vol1/pg_tblsp/PG_9.5_201510051 \
       /vol1/pg_tblsp/PG_9.6_201608131 standby.example.com:/vol1/pg_tblsp
 </programlisting>