Refactor buck external dependencies

Change-Id: Ia4b99493407eb7d4e893804cba6b944f758f085e
diff --git a/providers/pcep/BUCK b/providers/pcep/BUCK
index 3d57719..08eeea4 100644
--- a/providers/pcep/BUCK
+++ b/providers/pcep/BUCK
@@ -6,6 +6,7 @@
     '//protocols/pcep/pcepio:onos-protocols-pcep-pcepio',
     '//protocols/pcep/ctl:onos-protocols-pcep-ctl',
     '//apps/pcep-api:onos-apps-pcep-api',
+    '//lib:netty',
 ]
 
 onos_app (