Increase delay in ocserver.cpp sample to avoid missed notifications.

Increase delay in ocserver.cpp sample to avoid missed notifications.

This fixes IOT-726.
The sever started sending out presence notifications too quickly causing some
notifications to be missed.
Increased delay before notifications are sent out to make it convenient
for TE.

Change-Id: Ia6c92992f1000119a8f4dccde1de6bae4abeef5a
Signed-off-by: Mandeep Shetty <mandeep.shetty@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/3061
Reviewed-by: Mark Tung <mark.y.tung@intel.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Patrick Lankswert <patrick.lankswert@intel.com>