fw: move Forwarder::lookupFib to Strategy::lookupFib

refs #3664

Change-Id: Ib4dd2354d853f7d6455bf08bb6b863b5f77076c1
diff --git a/daemon/fw/strategy.hpp b/daemon/fw/strategy.hpp
index 5cea6a6..5b3cb2b 100644
--- a/daemon/fw/strategy.hpp
+++ b/daemon/fw/strategy.hpp
@@ -179,11 +179,10 @@
             std::initializer_list<const Face*> exceptFaces = std::initializer_list<const Face*>());
 
 protected: // accessors
+  /** \brief performs a FIB lookup, considering Link object if present
+   */
   const fib::Entry&
-  lookupFib(const pit::Entry& pitEntry)
-  {
-    return m_forwarder.lookupFib(pitEntry);
-  }
+  lookupFib(const pit::Entry& pitEntry) const;
 
   MeasurementsAccessor&
   getMeasurements()