文档上有一处错误

[chobitpapa]

文档 https://easywechat.com/6.x/pay/server.html#%E9%80%80%E6%AC%BE%E6%88%90%E5%8A%9F%E4%BA%8B%E4%BB%B6
有一处拼写错误，错误代码 $message = $server->getReqeustMessage(); ，应该为 ->getRequestMessage();

[TheNorthMemory]

已在 #2928 调整