[SHELL32] Mongoose's systray icon issue

Since the change from old to new explorer, this bug start happening, it's just easy to reproduce: open mongoose 3.6 and then right-click on its icon in systray, then choose the "Exit" option.

Here differs: old explorer acts as expected on windows, that is: the mongoose icon dissapear, unlike new explorer, where the old icon is remanent and if you open again mongoose, it draws a second icon.

Mongoose 3.6 https://mongoose.googlecode.com/files/mongoose-3.6.exe
Mongoose 3.6 source code (specifically the systray icon part) https://github.com/cesanta/mongoose/blob/3.6/main.c#L779