[REVIEW] fix for fdo#46975 , crash when using mouse wheel in input line

[Markus Mohrhard]

Hey,

[1] fixes a crash when you use the mouse wheel while a formula is in
the selected cell. We should not handle the mouse wheel event for the
input line.

I think this patch is safe. I did not move the handling of the event
to the parent window because this would result in scrolling through
the document even if you are over the input line.

Regards,
Markus

[1] http://cgit.freedesktop.org/libreoffice/core/commit/?id=77a517a467b3aa944e31b170162518f70da3793d