curl (bundled): with-darwinssl option is not compatible with OSX SDK 10.5

Change-Id: I3e8576926df875d73de10d5212adde2685c3a799
Reviewed-on: https://gerrit.libreoffice.org/8386
Tested-by: LibreOffice gerrit bot <gerrit@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>