Do not call event_del() for signals after fork(), just use sigaction()

directly instead - calling libevent functions after fork() w/o
event_reinit() is a bad idea, even if in this case it was harmless.

server.c

@@ -141,7 +141,7 @@ server_start(char *path)
 	/* event_init() was called in our parent, need to reinit. */
 	if (event_reinit(ev_base) != 0)
 		fatal("event_reinit failed");
-	clear_signals();
+	clear_signals(0);
 
 	logfile("server");
 	log_debug("server started, pid %ld", (long) getpid());