package/c-icap: add optional support for openssl

Optional OpenSSL was added with version 0.5.1:
https://sourceforge.net/p/c-icap/news/2017/03/the-c-icap-051-is-released-/
https://sourceforge.net/p/c-icap/code/1253/#diff-5

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/c-icap/c-icap.mk

@@ -54,6 +54,13 @@ else
 C_ICAP_CONF_OPTS += --without-ldap
 endif
 
+ifeq ($(BR2_PACKAGE_OPENSSL),y)
+C_ICAP_CONF_OPTS += --with-openssl
+C_ICAP_DEPENDENCIES += openssl
+else
+C_ICAP_CONF_OPTS += --without-openssl
+endif
+
 ifeq ($(BR2_PACKAGE_PCRE),y)
 C_ICAP_CONF_OPTS += --with-pcre
 C_ICAP_DEPENDENCIES += pcre