--lowest-speed-limit option is now available in aria2.changeOption.

--lowest-speed-limit option is now available in aria2.changeOption if
a download is waiting/paused in queue.

src/OptionHandlerFactory.cc

@@ -790,6 +790,7 @@ OptionHandlerFactory::createOptionHandlers()
     op->addTag(TAG_HTTP);
     op->setInitialOption(true);
     op->setChangeGlobalOption(true);
+    op->setChangeOptionForReserved(true);
     handlers.push_back(op);
   }
   {