sync up with CreateChannel API change

examples/cpp/helloworld/greeter_async_client.cc

@@ -89,7 +89,7 @@ class GreeterClient {
 
 int main(int argc, char** argv) {
   GreeterClient greeter(grpc::CreateChannel(
-      "localhost:50051", grpc::InsecureCredentials(), ChannelArguments()));
+      "localhost:50051", grpc::InsecureCredentials()));
   std::string user("world");
   std::string reply = greeter.SayHello(user);
   std::cout << "Greeter received: " << reply << std::endl;

examples/cpp/helloworld/greeter_client.cc

@@ -75,8 +75,7 @@ class GreeterClient {
 
 int main(int argc, char** argv) {
   GreeterClient greeter(
-      grpc::CreateChannel("localhost:50051", grpc::InsecureCredentials(),
-                          ChannelArguments()));
+      grpc::CreateChannel("localhost:50051", grpc::InsecureCredentials()));
   std::string user("world");
   std::string reply = greeter.SayHello(user);
   std::cout << "Greeter received: " << reply << std::endl;

examples/cpp/route_guide/route_guide_client.cc

@@ -235,8 +235,7 @@ int main(int argc, char** argv) {
   // Expect only arg: --db_path=path/to/route_guide_db.json.
   std::string db = examples::GetDbFileContent(argc, argv);
   RouteGuideClient guide(
-      grpc::CreateChannel("localhost:50051", grpc::InsecureCredentials(),
-                          ChannelArguments()),
+      grpc::CreateChannel("localhost:50051", grpc::InsecureCredentials()),
       db);
 
   std::cout << "-------------- GetFeature --------------" << std::endl;