Clean deletionrequest component
1. Enable allowbugdeletion in Administration -> Parameters -> Administrative Policies.
2. Once you have added all the soon to be deleted bugs to your trash component go back to the component list in the administration page (Administration -> Products -> LibreOffice -> Edit Components). You should see an “Action” column on the far right of the table with all your components with a Delete link. Find the deletionrequest component and click the associated “Delete” link.
3. Confirm the deletion.
4. Disable allowbugdeletion in Administration -> Parameters -> Administrative Policies
More Information: https://devzing.com/blog/index.php/how-to-delete-bugs-from-bugzilla/