Updating Sadis to latest snapshot to avoid runtime issues

Change-Id: I4da25facf157a4d2f6a7f19063d05de863e40f9d
diff --git a/app/pom.xml b/app/pom.xml
index 3cc4583..a623c3a 100644
--- a/app/pom.xml
+++ b/app/pom.xml
@@ -36,7 +36,7 @@
         <onos.app.title>IGMP proxy app</onos.app.title>
         <onos.app.url>http://opencord.org</onos.app.url>
         <onos.app.readme>IGMP implementation.</onos.app.readme>
-        <sadis.api.version>5.5.1</sadis.api.version>
+        <sadis.api.version>5.6.0-SNAPSHOT</sadis.api.version>
     </properties>
 
     <dependencies>