[MINOR] http: don't report the "haproxy" word on the monitoring response

Some people like to make the monitoring URL testable from unsafe locations.
Reporting haproxy's existence there can sometimes be problematic. This patch
should not be backported to 1.4 because it is possible, eventhough unlikely,
that some scripts rely on this word to appear there.
diff --git a/src/proto_http.c b/src/proto_http.c
index 379471e..af8adc9 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -75,7 +75,7 @@
 	"Connection: close\r\n"
 	"Content-Type: text/html\r\n"
 	"\r\n"
-	"<html><body><h1>200 OK</h1>\nHAProxy: service ready.\n</body></html>\n";
+	"<html><body><h1>200 OK</h1>\nService ready.\n</body></html>\n";
 
 const struct chunk http_200_chunk = {
 	.str = (char *)&HTTP_200,