Revert "component/haproxy: Version up"

This reverts commit b3afa3fe.

This change unexpectedly impacted ERP5 deployment.

component/haproxy/buildout.cfg

@@ -13,8 +13,8 @@ parts = haproxy
 [haproxy]
 recipe = slapos.recipe.cmmi
 shared = true
-url = https://www.haproxy.org/download/2.6/src/haproxy-2.6.8.tar.gz
-md5sum = 0b506378f1ade633d5b921f5806a5e82
+url = http://www.haproxy.org/download/2.6/src/haproxy-2.6.7.tar.gz
+md5sum = cfa36413f2bc5187ab34ffcdf71914d4
 configure-command = true
 # for Linux kernel 2.6.28 and above, we use "linux-glibc" as the TARGET,
 # otherwise use "generic".