Remove sharding key issue url from geo_events

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/174848



Merged-by: Omar Qunsul <oqunsul@gitlab.com>
Approved-by: Lucie Zhao <lzhao@gitlab.com>
Approved-by: Omar Qunsul <oqunsul@gitlab.com>
Co-authored-by: Shubham Kumar <shukumar@gitlab.com>