Don't explicitly set a height on button in notification delegate.

The default height is set by the button and is correct.

REVIEW: 119721
BUG: 338062

applets/notifications/package/contents/ui/NotificationPopup.qml

@@ -183,7 +183,6 @@ PlasmaCore.Dialog {
                     PlasmaComponents.Button {
                         text: modelData.text
                         width: theme.mSize(theme.defaultFont).width * 8
-                        height: theme.mSize(theme.defaultFont).width * 2
                         onClicked: {
                             executeAction(notificationProperties.source, modelData.id)
                             actionsColumn.visible = false