fix build failed

Signed-off-by: silenceper <[email protected]>

Author: silenceper

echo2_config.cc

@@ -14,8 +14,8 @@ namespace Configuration {
  */
 class Echo2ConfigFactory : public NamedNetworkFilterConfigFactory {
 public:
-  Network::FilterFactoryCb createFilterFactoryFromProto(const Protobuf::Message&,
-                                                        FactoryContext&) override {
+  absl::StatusOr<Network::FilterFactoryCb> 
+  createFilterFactoryFromProto(const Protobuf::Message&, FactoryContext&) override {
     return [](Network::FilterManager& filter_manager) -> void {
       filter_manager.addReadFilter(Network::ReadFilterSharedPtr{new Filter::Echo2()});
     };