don't clear equalizer when input-item changes

(cherry picked from commit 9c9dbd39)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt4/components/extended_panels.cpp

@@ -877,7 +877,6 @@ Equalizer::~Equalizer()
 
 void Equalizer::clean()
 {
-    ui.enableCheck->setChecked( false );
     enable();
 }
 /* Write down initial values */