This fixes#5675.
[Etienne Champetier <champetier.etienne@gmail.com>]
zabbix --with-mbedtls configuration option is sadly for libpolarssl
Attemp at support for mbedtls 2.1+:
https://support.zabbix.com/browse/ZBX-13237
As OpenSSL / GnuTLS are pretty big dependencies, default to no ssl for now
Signed-off-by: Oskari Lemmela <oskari@lemmela.net>