修复CocoaMQTTTimer在多线程下频繁操作出现的crash问题。

What's Changed

• fix: delegate类型异常导致的回调失败崩溃；读取数据时出现越界的崩溃 by @JyHu in #3

Full Changelog: v2.2.1...v2.2.2

What's Changed

• sendingmessages add thread safe by @LuoPengFei in #2

New Contributors

• @LuoPengFei made their first contribution in #2

Full Changelog: v2.1.9...v2.1.10

fix: 修复代码中强制解包可能导致的问题

• [FIX] 修复长链接数据交互过程中消息堆积的问题
• [FIX] 修复连接操作中properties值传递了value，而没有传递key的问题