Removed vestigial automatic download of BlueZ.

Removed vestigial automatic download of BlueZ.

The IoTivity Linux BLE transport no longer relies on headers found in
the BlueZ source distribution, such as <bluetooth/hci.h>, since it no
longer uses the kernel Bluetooth management API for LE advertising
related tasks.  LE advertising operations are now handled entirely
through BlueZ D-Bus API method calls.

Change-Id: I64ef5faac2fdac7aa15e2091b9a3bf44b786e1e5
Signed-off-by: Ossama Othman <ossama.othman@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/2031
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Erich Keane <erich.keane@intel.com>