Add session cache

src/freedombone-utils-web

     echo "    ssl_certificate_key /etc/ssl/private/${domain_name}.key;" >> $filename
     echo "    ssl_dhparam /etc/ssl/certs/${domain_name}.dhparam;" >> $filename
     echo '' >> $filename
+    echo '    ssl_session_cache  builtin:1000  shared:SSL:10m;' >> $filename
     echo '    ssl_session_timeout 60m;' >> $filename
     echo '    ssl_prefer_server_ciphers on;' >> $filename
     echo "    ssl_protocols $SSL_PROTOCOLS;" >> $filename