git-daemon: SysV needs the signal handler reinstated.

Fixes the bug on (amongst others) Solaris that only the first
child ever is reaped.
Signed-off-by: NStephen R. van den Berg <srb@cuci.nl>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

daemon.c

@@ -794,6 +794,7 @@ static void child_handler(int signo)
 		}
 		break;
 	}
+	signal(SIGCHLD, child_handler);
 }
 
 static int set_reuse_addr(int sockfd)