Fix misuse of project tracker type

Author: vitorguidi

src/clusterfuzz/_internal/cron/grouper.py

@@ -427,7 +427,7 @@ def group_testcases():
           issue_tracker = issue_tracker_utils.get_issue_tracker_for_testcase(
               testcase)
           logs.info(
-              f'Running grouping with issue tracker {issue_tracker.project()}, '
+              f'Running grouping with issue tracker {issue_tracker.project}, '
               f' for testcase {testcase_id}')
         except ValueError:
           logs.error('Couldn\'t get issue tracker for issue.')