Fix unicode issue in Demo 16

Author: pyscripter

Demos/Demo16/Example2/Unit1.pas

@@ -88,7 +88,7 @@ function TForm1.GetProperty(pSelf, Args : PPyObject) : PPyObject; cdecl;
           Result := VariantAsPyObject(rgSex.ItemIndex)
         else
           begin
-            PyErr_SetString (PyExc_AttributeError^, PAnsiChar(Format('Unknown property "%s"', [key])));
+            PyErr_SetString (PyExc_AttributeError^, PAnsiChar(UTF8Encode(Format('Unknown property "%s"', [key]))));
             Result := nil;
           end;
       end
@@ -136,7 +136,7 @@ function TForm1.SetProperty(pSelf, Args : PPyObject) : PPyObject; cdecl;
           end
         else
           begin
-            PyErr_SetString (PyExc_AttributeError^, PAnsiChar(Format('Unknown property "%s"', [key])));
+            PyErr_SetString (PyExc_AttributeError^, PAnsiChar(UTF8Encode(Format('Unknown property "%s"', [key]))));
             Result := nil;
           end;
       end