mxqd: Remove obsolete signal() calls in reaper

Now hat all signals are blocked, we don't need to ignore them.

mxqd.c

@@ -1061,12 +1061,6 @@ int reaper_process(struct mxq_server *server,struct mxq_group_list *glist, struc
 
     reset_signals();
 
-    signal(SIGINT,  SIG_IGN);
-    signal(SIGTERM, SIG_IGN);
-    signal(SIGQUIT, SIG_IGN);
-    signal(SIGHUP,  SIG_IGN);
-    signal(SIGXCPU, SIG_IGN);
-
     res = setsid();
     if (res < 0) {
         mx_log_warning("reaper_process setsid: %m");