A reference to a function in a "var _ = ..." init-time
initialization keeps the symbol live. Move references to
Config.EncryptTicket and Config.DecryptTicket into tests.
These references increase the size of an unused import of
crypto/tls by about 1MiB.
Change-Id: I6d62a6dcbd73e22972a217afcda7395e909b52cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/498595
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Damien Neil <dneil@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
