free choice of authgroups

[Nikos Mavrogiannopoulos]

Hello,
 I am implementing the ability to allow selecting a group on login
with ocserv, and I realized that the authgroup option of openconnect
is limited to the list provided by the server. For example if server
advertises group1 and group3, and I specify  group2, I get:
Auth choice "group2" not available.

Is that really necessary? It could be simply a warning message, as
there are cases where a server may support more groups that the ones
advertised.

regards,
Nikos