...not an SfxInt16Item.  Probably a typo introduced when adding the class with
bf3f3a6b "notebookbar: working number format
listbox".  (Found with -fsanitize=vptr when switching Calc to "View - User
Interface - Tabbed Compact".)

Change-Id: I6142b20750872037767e1857edeae83b1b2fa849
Reviewed-on: https://gerrit.libreoffice.org/73089
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>