message: [kythe] Fix new proto output -- set the fact name for the edges
diff: @@ -44,6 +44,7 @@ using ::kythe::proto::Entry;
  // Returns the Fact representation in Kythe's storage proto format.
  Entry ConvertEdgeToEntry(const Edge& edge) {
  Entry entry;
  + entry.set_fact_name("/");
  *entry.mutable_edge_kind() = edge.edge_name;
  *entry.mutable_source() = ConvertVnameToProto(edge.source_node);
  *entry.mutable_target() = ConvertVnameToProto(edge.target_node);
  