fix build_xfrm_sp_message index condition
fix build_xfrm_sp_message index condition

Index is not needed and not known if adding a policy. Seems to be copied from
build_xfrm_sp_delete_message.

HolyShitMan/libnl-1,HolyShitMan/libnl-1,HolyShitMan/libnl-1,HolyShitMan/libnl-1