Bountysource decided to update their Terms of service today:
2.13 Bounty Time-Out.
If no Solution is accepted within two years after a Bounty is posted, then the Bounty will be withdrawn and the amount posted for the Bounty will be retained by Bountysource. For Bounties posted before June 30, 2018, the Backer may redeploy their Bounty to a new Issue by contacting firstname.lastname@example.org before July 1, 2020. If the Backer does not redeploy their Bounty by the deadline, the Bounty will be withdrawn and the amount posted for the Bounty will be retained by Bountysource.
The issue is still open. If jolang does not contact the bountysource support to redeploy (I think that means to put the bounty to another issue) his bounty is retained by Bountysource.
Please make sure to redeploy your bounties to other issues. If you are unsure which one is good (=> with a high chance to be solved soon) feel free to ping the maintainers of the app.