added flag

Author: aklyuchev86

core/include/userver/utils/periodic_task.hpp

@@ -114,6 +114,8 @@ class PeriodicTask final {
     /// PeriodicTask::Start() calls engine::current_task::GetTaskProcessor()
     /// to get the TaskProcessor.
     engine::TaskProcessor* task_processor{nullptr};
+    /// @brief enabled allows to enable/disable timer during run
+    bool enabled{true};
   };
 
   /// Signature of the task to be executed each period.