MINOR: stream: prepare the hot refresh of timeouts

Define a stream function to allow to update the timeouts.
This commit is in preparation for the support of dynamic timeouts with
the set-timeout rule.
diff --git a/include/haproxy/stream.h b/include/haproxy/stream.h
index 766740c..f330260 100644
--- a/include/haproxy/stream.h
+++ b/include/haproxy/stream.h
@@ -343,6 +343,8 @@
 
 }
 
+int stream_set_timeout(struct stream *s, enum act_timeout_name name, int timeout);
+
 void service_keywords_register(struct action_kw_list *kw_list);
 struct action_kw *service_find(const char *kw);
 void list_services(FILE *out);
diff --git a/src/stream.c b/src/stream.c
index 690fe3e..65c67d1 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -811,6 +811,11 @@
 	}
 }
 
+int stream_set_timeout(struct stream *s, enum act_timeout_name name, int timeout)
+{
+	return 0;
+}
+
 /*
  * This function handles the transition between the SI_ST_CON state and the
  * SI_ST_EST state. It must only be called after switching from SI_ST_CON (or