MB-30149: Remove now-unused EWB_Engine::real_handle
MB-30149: Remove now-unused EWB_Engine::real_handle

Now we have unified the previously separate handle / engine, can
remove the redundant real_handle member.

Change-Id: Id5aa67b382460599ed1e9869eb92a371bc30bdd7
Reviewed-on: http://review.couchbase.org/98450
Reviewed-by: Ben Huddleston <6c0d3f0e87b08a8c49786ca528f2c4b1ad3d36f3@couchbase.com>
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine