qemu-options.hx: Add zoom-to-fit to option summary for gtk

The detailed help lists zoom-to-fit as valid option but it is missing
from the short option summary. Add it there too.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
1 file changed