Refactor buck external dependencies

Change-Id: Ia4b99493407eb7d4e893804cba6b944f758f085e
diff --git a/apps/vtn/vtnrsc/BUCK b/apps/vtn/vtnrsc/BUCK
index 846fc16..c4d5920 100644
--- a/apps/vtn/vtnrsc/BUCK
+++ b/apps/vtn/vtnrsc/BUCK
@@ -1,5 +1,6 @@
 COMPILE_DEPS = [
     '//lib:CORE_DEPS',
+    '//lib:KRYO',
     '//lib:org.apache.karaf.shell.console',
     '//cli:onos-cli',
     '//core/store/serializers:onos-core-serializers',