[ONOS-7882] Updating Yang Tools to 2.6.1 to address JSON serialization issue

Change-Id: I88148bf1c3dc4c38ad8c6d9f3abf0fe5aab0026a
diff --git a/lib/pom.xml b/lib/pom.xml
index 97e5c9b..48b83cd 100644
--- a/lib/pom.xml
+++ b/lib/pom.xml
@@ -44,7 +44,7 @@
         <netty4.version>4.1.8.Final</netty4.version>
         <openflowj.version>3.2.1.onos</openflowj.version>
         <onos-maven-plugin.version>1.12</onos-maven-plugin.version>
-        <onos-yang-tools.version>2.6</onos-yang-tools.version>
+        <onos-yang-tools.version>2.6.1</onos-yang-tools.version>
         <osgi.version>5.0.0</osgi.version>
         <karaf.version>3.0.8</karaf.version>
         <jersey.version>2.26</jersey.version>