Merge remote-tracking branch 'upstream/develop' into develop
Merge remote-tracking branch 'upstream/develop' into develop
 allow the minion to send empty dicts to the master

 the minion should be able to send empty dicts, because they
 appear every now and then. for example when pkg.list_upgrades
 reports that no upgrades are available.
Merge pull request #13840 from felskrone/fix_empty_event_dict

Fix empty event dict