package/qt5enginio: needs ssl

qt5enginio needs Qt5 with ssl support, a dependency could be added on
BR2_PACKAGE_QT5BASE_OPENSSL but this proposal was rejected in the first
iteration of this patch.

Qt5 has ssl support through libressl on Qt 5.6 or openssl in latest Qt
however we can't select libressl without adding a circular dependency as
some packages (such as sqlcipher) force openssl through
BR2_PACKAGE_OPENSSL_FORCE_LIBOPENSSL.

Any solution at the Kconfig level that tries to select libressl will
lead to circular dependencies. Since Qt 5.6 is more or less deprecated
anyway, and since it is not tested in the autobuilders, solve this with
a comment. The comment is only shown for Qt 5.6, when libressl is not
selected. Note that it is also shown when qt5enginio is not selected.

Fixes:
 - http://autobuild.buildroot.org/results/60678cab68ec9aa17184b8417b64b3b79adf428a



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>