bmcweb: make SSL enabling more effective

When specializing code, we know at compile time whether or not SSL will
be used, so we don't need to instantiate both types of
socket/server/app, when we only really care about one at runtime.

The size savings here aren't huge, but are worth doing, just for compile
times.

Change-Id: If4e9934a72eb0f12ce3755c6350e91b8ba485af1
Signed-off-by: Ed Tanous <ed.tanous@intel.com>