Fix change detection when using keyboard digits.

KTimeComboBox::timeChanged() is only emitted when using mouse
or when using up/down arrow.

When changing the time with other keys than up/down, like the
[0-9] keys, timeEdited() is emitted instead.

Not sure I understand the difference between the changed and edited
concepts. Might be a bug?

CCMAIL: john@layt.net
BUG: 308932