Adding some trace logging when setting last execution time for tasks

NzbDrone.Core/Jobs/TaskManager.cs

@@ -85,6 +85,7 @@ namespace NzbDrone.Core.Jobs
 
             if (scheduledTask != null)
             {
+                _logger.Trace("Updating last run time for: {0}", scheduledTask.TypeName);
                 _scheduledTaskRepository.SetLastExecutionTime(scheduledTask.Id, DateTime.UtcNow);
             }
         }