tdf#100898: custom animation panel is now Tab-reachable

the same fix as in 777bf677. Move on, nothing to see here

Change-Id: I4b4fe9f87b25c6e04329c052c532ab4da5a30d75
Reviewed-on: https://gerrit.libreoffice.org/48820Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>

sd/source/ui/sidebar/CustomAnimationPanel.cxx

@@ -34,6 +34,7 @@ CustomAnimationPanel::CustomAnimationPanel (
         rViewShellBase),
       mxFrame( rxFrame )
 {
+    SetStyle( GetStyle() | WB_DIALOGCONTROL );
 #ifdef DEBUG
     SetText(OUString("sd:CustomAnimationPanel"));
 #endif