catchunks: use ndn-cxx's RttEstimator

Refs: #4887
Change-Id: If24bea40a22909bf0fd9e49ec7b18330dbe336f2
diff --git a/tests/chunks/pipeline-interests-cubic.t.cpp b/tests/chunks/pipeline-interests-cubic.t.cpp
index b42728b..fa3aac8 100644
--- a/tests/chunks/pipeline-interests-cubic.t.cpp
+++ b/tests/chunks/pipeline-interests-cubic.t.cpp
@@ -80,8 +80,8 @@
     rttOptions.alpha = 0.125;
     rttOptions.beta = 0.25;
     rttOptions.k = 8;
-    rttOptions.minRto = Milliseconds(200);
-    rttOptions.maxRto = Milliseconds(4000);
+    rttOptions.minRto = RttEstimator::MillisecondsDouble(200);
+    rttOptions.maxRto = RttEstimator::MillisecondsDouble(4000);
     return rttOptions;
   }