kernel-netlink: Don't add replay state twice when updating SAs

kernel-netlink: Don't add replay state twice when updating SAs

The kernel includes the XFRMA_REPLAY_ESN_VAL attribute when dumping
SAs since it was added with 2.6.39.  So we basically added this attribute
twice to the message sent to the kernel, potentially exceeding the
message buffer if the window size is large.

The XFRMA_REPLAY_VAL attribute is only dumped since 3.19, so that might
still be relevant (Google seems to maintain a 3.18 kernel) and since we
have to query the current lifetime stats anyway, we can just avoid adding
this attribute twice.

Closes strongswan/strongswan#1967