Fixes: Non-regular keys are valid even with empty label
Fixes: Non-regular keys are valid even with empty label

RevBy: Jon Nordby
Only for keys with the default action (Key::ActionCommit), validity depends on
whether the key's label is empty. Backspace, space, return, symview etc. are no
longer bound to that check. Makes such keys press-able again.

KDE/plasma-maliit-plugins,develersrl/maliit-demo-qml,develersrl/maliit-demo-qml,KDE/plasma-maliit-plugins,maliit/plugins,develersrl/maliit-demo-qml,develersrl/maliit-demo-qml,KDE/plasma-maliit-plugins,maliit/plugins,RHawkeyed/plugins,RHawkeyed/plugins,maliit/plugins,maliit/plugins,RHawkeyed/plugins,RHawkeyed/plugins,KDE/plasma-maliit-plugins,RHawkeyed/plugins