Partially revert of 8e3a988b

This change was redundant, because switch to Manipulation panel is suppressed by disabling of Editors.
Moreover it did impossible to close all gizmos when it's really needed and caused a crash on "Select All" action, when some gizmo is open (SPE-1771)

src/slic3r/GUI/Gizmos/GLGizmosManager.cpp

@@ -173,8 +173,7 @@ void GLGizmosManager::reset_all_states()
     const EType current = get_current_type();
     if (current != Undefined)
         // close any open gizmo
-        if (!open_gizmo(current))
-            return;
+        open_gizmo(current);
 
     activate_gizmo(Undefined);
     m_hover = Undefined;