应该选择 CONFIG_IP_NF_TARGET_FULLCONENAT，而不是 CONFIG_NETFILTER_XT_TARGET_FULLCONENAT
IP_NF_TARGET_FULLCONENAT 包含了 NETFILTER_XT_TARGET_FULLCONENAT
```
config IP_NF_TARGET_FULLCONENAT
tristate "FULLCONENAT target support"
depends on NETFILTER_ADVANCED
select NETFILTER_XT_TARGET_FULLCONENAT
---help---
This is a backwards-compat option for the user's convenience
(e.g. when running oldconfig). It selects
CONFIG_NETFILTER_XT_TARGET_FULLCONENAT.
```
