man: Indent peers counters

In man page output the peers counters (resends, error, ...) was at the
same level as 'peers' command itself - this can be a bit confusing.

A2X manpage use ';;' format for similar problem (<destination_file> description
of "chunked, htmlhelp", "epub", "xhtml"), so use ';;' too.

Signed-off-by: Jan Friesse <jfriesse@redhat.com>