Remove global count methods.

In the previous commit, we removed the global count for our output. This commit removes
the logic as the only places where it was used was in recalculating the cache and since
the last commit, we do not use this value anymore

[MAILPOET-4487]

mailpoet/lib/API/JSON/v1/Settings.php

@@ -436,9 +436,6 @@ class Settings extends APIEndpoint {
     $segments = $this->segmentsRepository->findAll();
     foreach ($segments as $segment) {
       $this->subscribersCountsController->recalculateSegmentStatisticsCache($segment);
-      if ($segment->isStatic()) {
-        $this->subscribersCountsController->recalculateSegmentGlobalStatusStatisticsCache($segment);
-      }
     }
     $this->subscribersCountsController->recalculateSubscribersWithoutSegmentStatisticsCache();
     // remove redundancies from cache