Bump nlohmann-json externalproject to v3.3.0

This change bumps the external build of nlhomann-json to use
the latest v3.3.0 build.

Change-Id: I9da5f200fed0da34561e25f4505ceff9e9bd0bad
Signed-off-by: Jason M. Bills <jason.m.bills@linux.intel.com>