vmess节点不包含network项导致转换失败

[叙白]

在转换vmess节点时，如果节点格式为- {"server":"server","port":port,"uuid":"uuid","udp":true,"name":"name","type":"vmess","alterId":0}时，因为不包含network项而导致转换失败，报错为thread 'main' panicked at 'not yet implemented', src/util.rs:167:21，看了代码https://github.com/oluceps/clash2sing-box/blob/55710d2624c28f5b3f6d7b129e7a2377a28e5e65/src/util.rs#L167 这里可以返回None