Qt: remember volume on exit is the default

I don't want to be murdered in my sleep
(cherry picked from commit 0efead41)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt4/qt4.cpp

@@ -235,7 +235,7 @@ vlc_module_begin ()
                  UPDATER_DAYS_TEXT, false )
 #endif
 
-    add_bool( "qt-autosave-volume", false, SAVEVOL_TEXT,
+    add_bool( "qt-autosave-volume", true, SAVEVOL_TEXT,
               SAVEVOL_TEXT, true )
 #ifdef WIN32
     add_bool( "qt-disable-volume-keys"             /* name */,