MINOR: peers: store the pointer to the signal handler

We'll need it to unregister stopped peers sections.
diff --git a/src/peers.c b/src/peers.c
index d637e88..d39898a 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1393,8 +1393,8 @@
 	st->sync_task->process = process_peer_sync;
 	st->sync_task->expire = TICK_ETERNITY;
 	st->sync_task->context = (void *)st;
-	table->sync_task =st->sync_task;
-	signal_register_task(0, table->sync_task, 0);
+	table->sync_task = st->sync_task;
+	st->sighandler = signal_register_task(0, table->sync_task, 0);
 	task_wakeup(st->sync_task, TASK_WOKEN_INIT);
 }