mshow: only set cur when there is a new current message

mshow.c

@@ -839,6 +839,7 @@ main(int argc, char *argv[])
 		else
 			blaze822_loop(argc-optind, argv+optind, show);
 		if (!nflag) // don't set cur
+			if (newcur)
 				blaze822_seq_setcur(newcur);
 	}