Make our event base class independent of Symfony and follow PSR

Symfony is migrating towards a pure PSR event dispatcher, hence their
event class is POPO that implements the PSR stoppable event interface.
Since we can do that ourself and this change doesn't come with any API
changes (breakage), it's easy for us to become independent of Symfony
but also stay PSR-compliant at the same step.

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

1 files changed, 0 insertions, 0 deletions

diff --git a/3rdparty b/3rdparty
-Subproject 90a8336c3b51a3be5869569ef8e84949a1e6760
+Subproject 4466d782fafe2b53f3839156d10be0d3eacb47d