notification: Build when cloud is not enabled

notification: Build when cloud is not enabled

Problem was observed while building with:

scons VERBOSE=1 RELEASE=true SECURED=0 WITH_MQ=PUB,SUB,BROKER

  service/notification/examples/linux/notificationconsumer.c:268:23: \
  error: 'CLOUD_ADDRESS' undeclared (first use in this function)
  service/notification/examples/linux/notificationconsumer.c:268:23: \
  note: each undeclared identifier is reported only once for each function it appears in

Bug: https://jira.iotivity.org/browse/IOT-2244
Change-Id: I12f9a457ac7f838b90567794cbb030bdf80c3dc9
Signed-off-by: Philippe Coval <philippe.coval@osg.samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/19835
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Dave Thaler <dthaler@microsoft.com>
Reviewed-by: Uze Choi <uzchoi@samsung.com>