src: Sort names before std::set_difference

refs: #2029

Change-Id: I170f17cd69fd5a109913c6ebe9a13ab5552132a3
diff --git a/src/lsdb.cpp b/src/lsdb.cpp
index 427cc0b..0b7e4e7 100644
--- a/src/lsdb.cpp
+++ b/src/lsdb.cpp
@@ -152,6 +152,9 @@
           }
         }
       }
+
+      chkNameLsa->getNpl().sort();
+
       std::list<ndn::Name> nameToRemove;
       std::set_difference(chkNameLsa->getNpl().getNameList().begin(),
                           chkNameLsa->getNpl().getNameList().end(),