Fix compilation with no-compression OpenSSL builds and forks

Found because LibreSSL has OPENSSL_NO_COMP always-on, but this
conflicts with the way that _we_ turn off compression.  Patch from
dhill, who attributes it to "OpenBSD".  Fixes bug 12602; bugfix on
0.2.1.1-alpha, which introduced this turn-compression-off code.
Merge remote-tracking branch 'public/bug12602_024' into maint-0.2.5
Merge remote-tracking branch 'origin/maint-0.2.5'