MINOR: http_act: mark normalize-uri as experimental

normalize-uri http rule is marked as experimental, so it cannot be
activated without the global 'expose-experimental-directives'. The
associated vtc is updated to be able to use it.
diff --git a/src/http_act.c b/src/http_act.c
index 2fe235e..b8413f3 100644
--- a/src/http_act.c
+++ b/src/http_act.c
@@ -2449,7 +2449,7 @@
 		{ "deny",             parse_http_deny,                 0 },
 		{ "disable-l7-retry", parse_http_req_disable_l7_retry, 0 },
 		{ "early-hint",       parse_http_set_header,           0 },
-		{ "normalize-uri",    parse_http_normalize_uri,        0 },
+		{ "normalize-uri",    parse_http_normalize_uri,        KWF_EXPERIMENTAL },
 		{ "redirect",         parse_http_redirect,             0 },
 		{ "reject",           parse_http_action_reject,        0 },
 		{ "replace-header",   parse_http_replace_header,       0 },