submatview: do not reset retry waiter when materializer is reset

The materializer is often reset when an error is received. By resetting
the retryWaiter we effectively never wait. The retryWaiter should only
be reset when we get an event without error. This is done in
Materializer.updateView().

agent/submatview/materializer.go

@@ -181,7 +181,6 @@ func (m *Materializer) reset() {
 
 	m.view.Reset()
 	m.index = 0
-	m.retryWaiter.Reset()
 }
 
 func (m *Materializer) updateView(events []*pbsubscribe.Event, index uint64) error {