squid: Fix compilation without OpenSSL ENGINE support

OpenSSL 1.1 includes the header but support has to be checked in another
way.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

net/squid/patches/010-openssl-engine.patch

@@ -0,0 +1,11 @@
+--- a/src/ssl/support.cc
++++ b/src/ssl/support.cc
+@@ -485,7 +485,7 @@ Ssl::Initialize(void)
+ 
+     SQUID_OPENSSL_init_ssl();
+ 
+-#if HAVE_OPENSSL_ENGINE_H
++#ifndef OPENSSL_NO_ENGINE
+     if (::Config.SSL.ssl_engine) {
+         ENGINE_load_builtin_engines();
+         ENGINE *e;