Delay requesting push notification authorization until an actual account exists

[zeen]

It's a better user experience to not show an authorization prompt before the user has even added their account.

I submit my source code and allow Tigase to release the code as a part of Tigase's own software package under any license, either an open source or closed source.

[hantu85]

Thank you for providing this patch. I've reviewed it and it would work almost as expected. The only issue could be when the account would log in faster than the user answered the question to grant permission for SiskinIM to show notifications. In this case, some notifications for messages received before the user granted permission could be lost.

Most likely we will merge it to the next version of the SiskinIM.