windows: fix nonuniform behavior of zoom hotkeys

If a vv file is used or the hotkeys are customized using the --hotkeys cmd option, all hotkeys that are not explicitly requested get disabled, this includes the zomm hotkeys.

As a consequence, the labels for zoom actions in the menu disappear. However, the user can still perform these actions using the keys on the numpad which are handled separately.

To fix it, check that the normal zoom hotkeys are enabled before enabling the keypad ones.

Related to: https://bugzilla.redhat.com/show_bug.cgi?id=1791261

Signed-off-by: Jakub Janků jjanku@redhat.com