Fixed: [pasteboard declareTypes:… owner:nil]; would emit a warning.

Without this fix, declaring a type with a nil owner would cause a "DEPRECATED: object cannot be nil" warning to be issued.

This fix now allows a nil owner without warning.

AppKit/CPPasteboard.j

@@ -191,10 +191,12 @@ var CPPasteboards = nil,
     _owners = @{};
     _provided = @{};
 
-    var count = _types.length;
-
-    while (count--)
-        [_owners setObject:anOwner forKey:_types[count]];
+    if (anOwner)
+    {
+        var count = _types.length;
+        while (count--)
+            [_owners setObject:anOwner forKey:_types[count]];
+    }
 
     if (_nativePasteboard && shouldUpdate)
     {
@@ -205,6 +207,7 @@ var CPPasteboards = nil,
         _nativePasteboard.declareTypes_(nativeTypes);
         _changeCount = _nativePasteboard.changeCount();
     }
+
     return ++_changeCount;
 }