message: StateObjectsRegistry: do not show message about purged objects if there are none (close DiligentGraphics/DiligentTools#160)
diff: @@ -186,6 +186,7 @@ public:
  It = NextIt;
  }
  + if (NumPurgedObjects > 0)
  LOG_INFO_MESSAGE("Purged ", NumPurgedObjects, " deleted objects from the ", m_RegistryName, " registry");
  }
  