Abstracting testbed prepended name components

Change-Id: Ieb3b3971fb09e31ddb15d85b5907ee7be41ef6ae
diff --git a/src/file-manifest.cpp b/src/file-manifest.cpp
index 6310b20..1ccb4ef 100644
--- a/src/file-manifest.cpp
+++ b/src/file-manifest.cpp
@@ -65,7 +65,7 @@
                                               manifestPrefix.toUri() + " and "     +
                                               full_path.toUri()));
   }
-  ndn::Name manifestName = "/ndn/multicast/NTORRENT/";
+  ndn::Name manifestName(SharedConstants::commonPrefix + std::string("/NTORRENT/"));
   // Rebuild the name to be the suffix from the matching component
   for (auto it = (name_component_iter.base() - 1); full_path.end() != it; ++it) {
     manifestName.append(*it);
@@ -331,4 +331,4 @@
 }
 
 }  // end ntorrent
-}  // end ndn
\ No newline at end of file
+}  // end ndn