add comment on where to stop

bug1240930-253/mozilla/series-append

@@ -1,6 +1,7 @@
 1377911-1-57a1.patch
 1377911-2-57a1.patch
 1393848-57a1.patch
+#StopHere
 1437942-62a1.patch
 1240930-80a1.patch
 1457321-1only-62a1.patch