tdf#131254 Follow-up Prevent extra eventqueue empty call.

When two advance timing set slides in a row, there is another
extra forceEmpty call that disables timing setting.
Follow up commit 80f386f787ad59936ead2022e6d932a6d441c6e9

Change-Id: I8e70ebf57328b51eab2baca9728a0f8e0561120c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91367
Tested-by: Jenkins
Reviewed-by: Andras Timar <andras.timar@collabora.com>
(cherry picked from commit 14a0727889699128f02ac0a79bdce0103c89bc01)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91303
diff --git a/slideshow/source/engine/effectrewinder.cxx b/slideshow/source/engine/effectrewinder.cxx
index 1a1dc063..944374d 100644
--- a/slideshow/source/engine/effectrewinder.cxx
+++ b/slideshow/source/engine/effectrewinder.cxx
@@ -173,7 +173,6 @@ bool EffectRewinder::rewind (

    // Abort (and skip over the rest of) any currently active animation.
    mrUserEventQueue.callSkipEffectEventHandler();
    mrEventQueue.forceEmpty();

    const int nSkipCount (mnMainSequenceEffectCount - 1);
    if (nSkipCount < 0)