Access2Base - Bug when event triggered by toolbar button

Argument given by LO to macro triggered by toolbar button is an integer, not an object.
This should not cause a visible error for the end-user from within the Events() Sub

Change-Id: I4a307270b0d5cf2992b3bb304deb8cd30222dd95
Reviewed-on: https://gerrit.libreoffice.org/9452
Reviewed-by: Lionel Elie Mamane <lionel@mamane.lu>
Tested-by: Lionel Elie Mamane <lionel@mamane.lu>