Don't check the return value of the SOAP call

This will be false in case of time-consuming background tasks.
We have to keep the "fire and forget".

src/BackgroundTasks/Implementation/TaskManager/AsyncTaskManager.php

@@ -68,12 +68,9 @@ public function run(Bucket $bucket): void
         );
 
         try {
-            $result = $soap_client->call(self::CMD_START_WORKER, array(
+            $soap_client->call(self::CMD_START_WORKER, array(
                 $session_id . '::' . $client_id,
             ));
-            if ($result === false) {
-                throw new ilException("SOAP call returned false");
-            }
         } catch (\Throwable $t) {
             $DIC->logger()->bgtk()->warning($t->getMessage());
             $DIC->logger()->bgtk()->warning("Calling webserver failed, fallback to sync version");