Win32: do not map Volume keys by default

On Windows, it seems people expect volume keys to control the master
volume...
I'm not going to fight this fight with our users during support...

Ref #9373

src/libvlc-module.c

@@ -2292,8 +2292,15 @@ vlc_module_begin ()
 #   define KEY_NAV_LEFT           "Left"
 #   define KEY_NAV_RIGHT          "Right"
 #   define KEY_QUIT               "Ctrl+q"
+
+#ifdef _WIN32 /* On Windows, people expect volume keys to control the master */
+#   define KEY_VOL_UP             "Ctrl+Up"
+#   define KEY_VOL_DOWN           "Ctrl+Down"
+#else
 #   define KEY_VOL_UP             "Ctrl+Up\tVolume Up"
 #   define KEY_VOL_DOWN           "Ctrl+Down\tVolume Down"
+#endif
+
 #   define KEY_VOL_MUTE           "m\tVolume Mute"
 #   define KEY_SUBDELAY_UP        "h"
 #   define KEY_SUBDELAY_DOWN      "g"