Fix focus after pressing Enter in EditorSpinSlider

With the change from Popup to Controls for the Input-Node, it becomes
necessary to adjust focus after hiding the Input-Node to the initial
Control.

editor/editor_spin_slider.cpp

@@ -582,6 +582,7 @@ void EditorSpinSlider::_value_focus_exited() {
 		//tab was pressed
 	} else {
 		//enter, click, esc
+		grab_focus();
 	}
 }