REGTESTS: peers: leave a bit more time to peers to synchronize

REGTESTS: peers: leave a bit more time to peers to synchronize

tls_basic_sync_wo_stkt_backend fails once every 200 runs for me. This
seems to be because the startup delay doesn't always allow peers to
perform a simultaneous connect, close and new attempt. With 3s I can't
see it fail anymore. In addition the long "delay 0.2" are still way too
much since we do not really care about the startup order in practice.

(cherry picked from commit c38200563645e314bd0af59958c75171cca59d4b)
Signed-off-by: Willy Tarreau <w@1wt.eu>