With the removal of the support for sendemail.smtpssl in the preceding
commit the parsing of sendemail.smtpencryption is no longer special,
and can by moved to %config_settings.
This gets us rid of an unconditional call to Git::config(), which as
we'll see in subsequent commits matters for startup performance.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>