package/hostapd: enable MD4 in openssl

package/hostapd: enable MD4 in openssl

Hostapd assumes that openssl always provides MD4 support. However MD4
support in openssl has become optional since  commit a83d41867c8d
("package/libopenssl: add option to enable some features").

Select openssl MD4 support in hostapd Kconfig to avoid build failures.

Fixes:
http://autobuild.buildroot.net/results/09ce1d8009da98cd2a3f2c8488abaa9f060a9d6b/

Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>