Check for spyder updates on github releases using a QThread.

def check_updates(self, startup=False):
        """
        Check for spyder updates on github releases using a QThread.
        """
        from spyder.workers.updates import WorkerUpdates

        # Disable check_updates_action while the thread is working
        self.check_updates_action.setDisabled(True)

        if self.thread_updates is not None:
            self.thread_updates.terminate()

        self.thread_updates = QThread(self)
        self.worker_updates = WorkerUpdates(self, startup=startup)
        self.worker_updates.sig_ready.connect(self._check_updates_ready)
        self.worker_updates.sig_ready.connect(self.thread_updates.quit)
        self.worker_updates.moveToThread(self.thread_updates)
        self.thread_updates.started.connect(self.worker_updates.start)
        self.thread_updates.start()