Upgrade net/axa to version 2.2.0:

• Add timestamp indexing
• Fix negotiation of AXA protocol version upon successful connection

Simplify and unbreak CONFIGURE_ENV. Passing /usr/lib/libssl.so to the
linker as an object when building libaxa.so does not cause the linker to
record libssl as a dependency.

Sponsored by: Farsight Security, Inc.