Fixes two related security vulnerabilities (CVE-2020-15078) which under
very specific circumstances allow tricking a server using delayed
authentication (plugin or management) into returning a PUSH_REPLY before
the AUTH_FAILED message, which can possibly be used to gather
information about a VPN setup.
This release also includes other bug fixes and improvements.
Signed-off-by: Magnus Kroken <mkroken@gmail.com>