MINOR: muxes: export the timeout and shutr task handlers

These ones appear often in "show tasks" so it's handy to make them
resolve.
diff --git a/src/mux_h1.c b/src/mux_h1.c
index 5c826c6..0a33427 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -267,7 +267,7 @@
 static int h1_process(struct h1c *h1c);
 /* h1_io_cb is exported to see it resolved in "show fd" */
 struct task *h1_io_cb(struct task *t, void *ctx, unsigned short state);
-static struct task *h1_timeout_task(struct task *t, void *context, unsigned short state);
+struct task *h1_timeout_task(struct task *t, void *context, unsigned short state);
 static void h1_shutw_conn(struct connection *conn, enum cs_shw_mode mode);
 static void h1_wake_stream_for_recv(struct h1s *h1s);
 static void h1_wake_stream_for_send(struct h1s *h1s);
@@ -2871,7 +2871,7 @@
 /* Connection timeout management. The principle is that if there's no receipt
  * nor sending for a certain amount of time, the connection is closed.
  */
-static struct task *h1_timeout_task(struct task *t, void *context, unsigned short state)
+struct task *h1_timeout_task(struct task *t, void *context, unsigned short state)
 {
 	struct h1c *h1c = context;
 	int expired = tick_is_expired(t->expire, now_ms);