macosx: remove level 0 from the post-pp menu

(cherry picked from commit e6578e3d925581af40e6ba102e1664b38a41b0e5)
Signed-off-by: David Fuhrmann <dfuhrmann@videolan.org>

modules/gui/macosx/MainMenu.m

@@ -279,11 +279,11 @@ static VLCMainMenu *_o_sharedInstance = nil;
     [o_mitem setTag: -1];
     [o_mitem setEnabled: YES];
     [o_mitem setTarget: self];
-    for (NSUInteger x = 0; x < 7; x++) {
+    for (NSUInteger x = 1; x < 7; x++) {
         [o_mu_ffmpeg_pp addItemWithTitle:[NSString stringWithFormat:_NS("Level %i"), x]
                                                action:@selector(togglePostProcessing:)
                                         keyEquivalent:@""];
-        o_mitem = [o_mu_ffmpeg_pp itemAtIndex:x+1];
+        o_mitem = [o_mu_ffmpeg_pp itemAtIndex:x];
         [o_mitem setEnabled: YES];
         [o_mitem setTag:x];
         [o_mitem setTarget: self];