Merge pull request #240 from stanley-cheung/node_route_guide_minor_fix

doc fix: add db_path param to node route_guide_server command
diff --git a/ruby/route_guide/route_guide_server.rb b/ruby/route_guide/route_guide_server.rb
index 8f12ba2..2b2b808 100755
--- a/ruby/route_guide/route_guide_server.rb
+++ b/ruby/route_guide/route_guide_server.rb
@@ -203,7 +203,7 @@
   port = '0.0.0.0:50051'
   s = GRPC::RpcServer.new
   s.add_http2_port(port)
-  logger.info("... running insecurely on #{port}")
+  GRPC.logger.info("... running insecurely on #{port}")
   s.handle(ServerImpl.new(feature_db))
   s.run
 end