Add cleanup subscribers counts cache

[MAILPOET-3714]

lib/API/JSON/v1/Settings.php

@@ -259,6 +259,8 @@ class Settings extends APIEndpoint {
       }
     }
     $this->subscribersCountsController->recalculateSubscribersWithoutSegmentStatisticsCache();
+    // remove redundancies from cache
+      $this->subscribersCountsController->removeRedundancyFromStatisticsCache();
     return $this->successResponse();
   }
 }