haproxy-devel: fixes from upstream

[PATCH 55/58] BUG/MEDIUM: connection: fix proxy v2 header again!
[PATCH 56/58] BUG/MINOR: server: move the directive #endif to the end
[PATCH 57/58] BUG/MINOR: Fix search for -p argument in systemd
[PATCH 58/58] MEDIUM: Improve signal handling in systemd wrapper.

Signed-off-by: Thomas Heil <heil@terminal-consulting.de>