Alexander Reelsen 3a263d91f6 Ensure watcher email action message ids are always unique (#56574)
If an email action is used in a foreach loop, message ids could have
been duplicated, which then get rejected by the mail server.

This commit introduces an additional static counter in the email action
in order to ensure that every message id is unique.
2020-05-14 10:36:00 +02:00
..