Querks when specifying the CKAID of a raw RSA key in a basic IKEv2
connection.

When loading a connection, pluto uses the search sequence:

     CKAID -> [pubkey|certificate] -> private key

things don't go well:

- "ipsec auto --add westnet-eastnet-ikev2" which specifies CKAIDs and
  RSASIGKEYs doesn't work as the RSASIGKEYs only get added to the
  pubkey list _after_ the connection has been added; and of course that
  fails because they haven't yet been added ...

- having the pubkey in /etc/ipsec.secrets doesn't help: they get
  stored in the private-key list, not the pubkey one.  Since pubkeys
  shouldn't even be in ipsec.secrets, let's ignore this.

- having a direct CKAID -> private key lookup would help with the
  private key but not for the pubkey side of things (as an aside, it
  is arguable that the CKAID, and not the ID, is a better tool for
  identifying keys)

But there's a work-around:

1. "ipsec auto --add westnet-eastnet-ipv4"

   this has the side effect of adding the RSASIGKEYs to the pubkey
   list

2. "ipsec auto --add westnet-eastnet-ikev2-ckaid"

   loads because the line above loaded the RSASIGKEYs.
