TypeError: self.save is not a function in the console while saving notifications preferences

Go to your notifications settings, open the console (F12), enable some notifications types.

You end up with "TypeError: self.save is not a function" in the console.

Thanks mflorea for having found it: https://github.com/xwiki/xwiki-platform/commit/d5bd1aa412bf782c5dbc9e19a759725ab2baf06d#r31150622