Don't pass escape key event to SfxDockingWindow from sidebar

...docking window

Missed this in recent rework concerning key input events in
SidebarDockingWindow, tdf#125525 Allow shortcut keys from sidebar
docking window.

Change-Id: I53906251918874d2613795cb06a3e6ef07509bd8
Reviewed-on: https://gerrit.libreoffice.org/73192
Tested-by: Jenkins
Reviewed-by: Jim Raykowski <raykowj@gmail.com>

sfx2/source/sidebar/SidebarDockingWindow.cxx

@@ -140,6 +140,7 @@ bool SidebarDockingWindow::EventNotify(NotifyEvent& rEvent)
             case KEY_DELETE:
             case KEY_INSERT:
             case KEY_RETURN:
+            case KEY_ESCAPE:
             {
                 return true;
             }