BUG/MEDIUM: peers: reset commitupdate value in new conns

BUG/MEDIUM: peers: reset commitupdate value in new conns

The commitupdate value of the table is used to check if the update
is still pending for a push for all peers. To be sure to not miss a
push we reset it just after a handshake success.

This patch should be backported on all supported branches ( >= 1.6 )

(cherry picked from commit cc9cce9351c2d64476dbe2f35c43cde8a3f97ebe)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit cd0a30e441faa7d2c6d71f9541d092140f04e6ef)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 228bf0088078ea872fcab61db93a6c306c2d0d0c)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>