Reduce the actions for static data delivery

[renepickhardt]

The static data delivery service should be able to detect if we have the following situation

(a)--->(b)
and
(a)--->(c)

now (b) makes an update triggering actions for (a) to be renewed. Before (a) has worked in this (c) makes another update also triggering actions for (a). This should not cause (a) to be updated twice.