route: handle zero cost links

refs: #4978

Change-Id: I461bdac9e10cb8362a7624b177ee68aa20d3ff3e
diff --git a/src/lsdb.cpp b/src/lsdb.cpp
index 01c1ee0..1e3cf1b 100644
--- a/src/lsdb.cpp
+++ b/src/lsdb.cpp
@@ -218,12 +218,10 @@
           m_namePrefixTable.addEntry(name, nlsa.getOrigRouter());
         }
       }
-    }
-    if (nlsa.getOrigRouter() != m_confParam.getRouterPrefix()) {
-      ndn::time::system_clock::Duration duration = nlsa.getExpirationTimePoint() -
-                                                   ndn::time::system_clock::now();
+      auto duration = nlsa.getExpirationTimePoint() - ndn::time::system_clock::now();
       timeToExpire = ndn::time::duration_cast<ndn::time::seconds>(duration);
     }
+
     nlsa.setExpiringEventId(scheduleNameLsaExpiration(nlsa.getKey(),
                                                       nlsa.getLsSeqNo(),
                                                       timeToExpire));