core: fix external events injection

This patch fixes a regression that cause external events injection to
fail MLA validation.
The problem was in the DB squashing of 3.2 done in commit
11bc072021a28560261dc2601f8fd106c9c322e6

Change-Id: I8703aa99b8f630e99110de8fc523a55c63fd10c1
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1173947
Signed-off-by: emesika <emesika@redhat.com>