Temp fix for broken multicast presence after WiFi/Ethernet merge.

Temp fix for broken multicast presence after WiFi/Ethernet merge.

This is a temporary fix.
The multicast notifications from server side need remote endpoint to be
null in caipadapter.c::CAIPSendDataThread().
But the function signature called from the RI layer into the CA layer
to send responses takes a CARemoteEndpoint struct which cannot be null.

The temp fix is to make caipclient.c think that a response is multicast if
the remoteAddress is the fixed multicast ip 224.0.1.187.

Change-Id: I6720ceb123d044b9c2aa510d41488b5003324e4e
Signed-off-by: Mandeep Shetty <mandeep.shetty@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/922
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Sakthivel Samidurai <sakthivel.samidurai@intel.com>
Reviewed-by: Uze Choi <uzchoi@samsung.com>