Change to another wallet while syncing - The wallet file is blocked sometimes.

[juanky201271]

Only sometimes, when you try to change to another wallet and the App is syncing, the App is not able to remove the wallet file, likely because the App is writing the wallet file & is blocked when it try to delete it.

I experienced a couple of times in production, and the user can be upset about this, obviously.

This problem is really similar to that: #601

I think can be a good idea to run the interrupt_sync.... to true when the user start the action of Change to another server, so when the user confirm that, the syncing hopefully is finished, and the wallet file will be remove with no issues.

@Edicksonjga I know you experienced this as well, feel free to comment anything you want about it.

[juanky201271]

Fix: The app stop the syncing process right before the App is removing the actual wallet file, this way nothing can blocked this file.