Fixed issue where Scons param 'LOGGING' is assigned wrong default value.

Fixed issue where Scons param 'LOGGING' is assigned wrong default value.

This will fix issue reported on the IoTivity dev list where the flag
for Stack Logging (ie. TB_LOG) was not being enabled in any Debug build
that wasn't invoked by using exactly "false" for the Scons param
'RELEASE'.

Change-Id: I19677113d3d195059cf15c7073adc6418a152a1f
Signed-off-by: Joseph Morrow <joseph.l.morrow@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/1130
Reviewed-by: Erich Keane <erich.keane@intel.com>
Reviewed-by: John Light <john.j.light@intel.com>
Reviewed-by: Doug Hudson <douglas.hudson@intel.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>