Added support for bits proxy, where ONOS bits can survive borrow/return cycles.

Change-Id: I0ab9bac26bd88a246925750d26baaab228a37136
diff --git a/tools/test/scenarios/prerequisites.xml b/tools/test/scenarios/prerequisites.xml
index 4b963dd..ad6545d 100644
--- a/tools/test/scenarios/prerequisites.xml
+++ b/tools/test/scenarios/prerequisites.xml
@@ -24,5 +24,7 @@
             <step name="Check-Passwordless-Login-${#}"
                   exec="ssh -n -o ConnectTimeout=3 -o PasswordAuthentication=no ${ONOS_USER}@${OC#} date"/>
         </parallel>
+        <step name="Check-Passwordless-Login-Proxy" if="${OCT}"
+              exec="ssh -n -o ConnectTimeout=3 -o PasswordAuthentication=no ${ONOS_USER}@${OCT} date"/>
     </group>
 </scenario>