fixed bug with connection to first node

@@ -68,6 +68,8 @@ public class RuleChainUpdateMsgConstructor {
                     .addAllRuleChainConnections(constructRuleChainConnections(ruleChainMetaData.getRuleChainConnections()));
             if (ruleChainMetaData.getFirstNodeIndex() != null) {
                 builder.setFirstNodeIndex(ruleChainMetaData.getFirstNodeIndex());
+            } else {
+                builder.setFirstNodeIndex(-1);
             }
             builder.setMsgType(msgType);
             return builder.build();