REGTESTS: remove unsupported "stats bind-process" keyword

reg-tests/connection/proxy_protocol_random_fail.vtc fails due to
"stats bind-process":

***  h1    debug|[ALERT]    (1476756) : config : parsing [/tmp/haregtests-2023-04-22_19-24-10.diuT6B/vtc.1476661.74f1092e/h1/cfg:7] : 'stats' is
***  h1    debug|not supported anymore.
diff --git a/reg-tests/connection/proxy_protocol_random_fail.vtc b/reg-tests/connection/proxy_protocol_random_fail.vtc
index bcaa03c..1ae33de 100644
--- a/reg-tests/connection/proxy_protocol_random_fail.vtc
+++ b/reg-tests/connection/proxy_protocol_random_fail.vtc
@@ -25,7 +25,6 @@
 haproxy h1 -conf {
     global
         tune.ssl.default-dh-param 2048
-        stats bind-process 1
         log ${Slog_1_addr}:${Slog_1_port} len 2048 local0 debug err
 
     defaults