MINOR: tcp-act: Add set-src/set-src-port for "tcp-request content" rules

If it possible to set source IP/Port from "tcp-request connection",
"tcp-request session" and "http-request" rules but not from "tcp-request
content" rules. There is no reason for this limitation and it may be a
problem for anyone wanting to call a lua fetch to dynamically set source
IP/Port from a TCP proxy. Indeed, to call a lua fetch, we must have a
stream. And there is no stream when "tcp-request connection/session" rules
are evaluated.

Thanks to this patch, "set-src" and "set-src-port" action are now supported
by "tcp_request content" rules.

This patch is related to the issue #1303. It may be backported to all stable
versions.

(cherry picked from commit 19bbbe05629ea947dd60d5b96d96f0066b047b97)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/tcp_act.c b/src/tcp_act.c
index d55475c..a6f0596 100644
--- a/src/tcp_act.c
+++ b/src/tcp_act.c
@@ -318,6 +318,8 @@
 INITCALL1(STG_REGISTER, tcp_req_sess_keywords_register, &tcp_req_sess_actions);
 
 static struct action_kw_list tcp_req_cont_actions = {ILH, {
+	{ "set-src",      tcp_parse_set_src_dst },
+	{ "set-src-port", tcp_parse_set_src_dst },
 	{ "set-dst"     , tcp_parse_set_src_dst },
 	{ "set-dst-port", tcp_parse_set_src_dst },
 	{ "silent-drop",  tcp_parse_silent_drop },