skins2: setOpacity moved to a better place

Opacity used to work only on newly loaded skins, but failed to work from
skins restored from a previous session.

modules/gui/skins2/src/window_manager.cpp

@@ -425,7 +425,6 @@ void WindowManager::showAll( bool firstTime ) const
         {
             (*it)->show();
         }
-        (*it)->setOpacity( m_alpha );
     }
 }
 

modules/gui/skins2/src/window_manager.hpp

@@ -120,7 +120,8 @@ public:
     void raise( TopWindow &rWindow ) const { rWindow.raise(); }
 
     /// Show the given window
-    void show( TopWindow &rWindow ) const { rWindow.show(); }
+    void show( TopWindow &rWindow ) const
+        { rWindow.show(); rWindow.setOpacity( m_alpha); }
 
     /// Hide the given window
     void hide( TopWindow &rWindow ) const { rWindow.hide(); }