Remove toolbar-spacer if the menu has been disabled

Remove toolbar-spacer if the menu has been disabled

Aligning the control-button to the right of Dolphin has the problem
that sub-menus might be opened on the left of the menu if the Dolphin
window reaches the right of the desktop. So the toolbar-spacer has
been removed and a default label has been applied to the control-button
to increase the target-area for opening the menu.