Revert "Makefile: Add httpserver rule"

This reverts commit a39cde7853e742846cd2a8a79cc41699d36e6dee. I applied
the broken version.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
Makefile: Add httpserver rule

The httpserver is part of the compilation of the mgmt.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>