auth-token: Fix building with --disable-server

auth-token: Fix building with --disable-server

The final patches of the auth-token hmac support patches had a typo in
the P2MP_SERVER fencing breaking --disable-server builds.  It used #if
instead of #ifdef.

While at it, also fix another missing P2MP_SERVER fencing causing the
compiler to complain about an unused variable in push.c

Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20190927224536.27480-2-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg18875.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>