The combination +@IPV6:kmod-ipsec6 is not valid, the +a:b
syntax implies the @. Fix it.
Fixes: 2e6b6f9fcaae ("kernel: add @IPv6 dependency to ipv6 modules")
Reported-by: Oldřich Jedlička (@oldium)
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>