Remove recommendation of BountySource

There are reports that they aren't paying bounties nor returning money to people.
Plus the website seems to not work properly anymore.
Probably abandoned as a service.

_site/donate.html

@@ -89,13 +89,6 @@ <h3>Donation options</h3>
     </tr>
   </tbody>
 </table>
-<br>
-<p><b>BountySource DISCLAIMER:</b> A feature implementation or a bug fix might not get accepted and instead be rejected.
-Some of the reasons might be code quality that isn't up to par with the rest of the project, poor code architecture/engineering, implementing a feature that doesn't actually fit with qBittorrent or we don't want to have it.
-Generally objective reasons. The only subjective reason is rejecting a feature simply because we don't want it in qBittorrent (however we take the community's desires into consideration too).
-We won't reject a feature/bugfix simply to deny a person a bounty or to claim the bounty for ourselves or another affiliated person.
-Lastly, due to workload and our limited time `Pull Requests` may not be reviewed/merged in a timely manner.
-</p>
 
               </div>
             </div>

donate.liquid

@@ -42,10 +42,3 @@ If you want to give money for specific features being implemented, take a look a
     </tr>
   </tbody>
 </table>
-<br>
-<p><b>BountySource DISCLAIMER:</b> A feature implementation or a bug fix might not get accepted and instead be rejected.
-Some of the reasons might be code quality that isn't up to par with the rest of the project, poor code architecture/engineering, implementing a feature that doesn't actually fit with qBittorrent or we don't want to have it.
-Generally objective reasons. The only subjective reason is rejecting a feature simply because we don't want it in qBittorrent (however we take the community's desires into consideration too).
-We won't reject a feature/bugfix simply to deny a person a bounty or to claim the bounty for ourselves or another affiliated person.
-Lastly, due to workload and our limited time `Pull Requests` may not be reviewed/merged in a timely manner.
-</p>