tnc-ifmap: Remove prototypical IF-MAP plugin

This was primarily used in our labs to visualize some TNC aspects but
the third-party daemon and frontend we used have not seen any development
in a decade.  There never was any industry interest in this protocol
anyway, so just remove it.

conf/plugins/tnc-ifmap.opt

@@ -1,21 +0,0 @@
-charon.plugins.tnc-ifmap.client_cert =
-	Path to X.509 certificate file of IF-MAP client.
-
-charon.plugins.tnc-ifmap.client_key =
-	Path to private key file of IF-MAP client.
-
-charon.plugins.tnc-ifmap.device_name =
-	Unique name of strongSwan server as a PEP and/or PDP device.
-
-charon.plugins.tnc-ifmap.renew_session_interval = 150
-	Interval in seconds between periodic IF-MAP RenewSession requests.
-
-charon.plugins.tnc-ifmap.server_uri = https://localhost:8444/imap
-	URI of the form [https://]servername[:port][/path].
-
-charon.plugins.tnc-ifmap.server_cert =
-	Path to X.509 certificate file of IF-MAP server.
-
-charon.plugins.tnc-ifmap.username_password =
-	Credentials of IF-MAP client of the form username:password. If set, make
-	sure to adjust the permissions of the config file accordingly.