external/grpc: Update gRPC README.md
update `gRPC README.md` with an additional `ldconfig` installation step that was previously missed.
@@ -39,6 +39,7 @@ $ ./configure
$ make
$ make check
$ [sudo] make install
+$ [sudo] ldconfig
```
As a reference, please consult [C++ Installation Instructions](https://github.com/google/protobuf/blob/master/src/README.md) for details on how to install `Protobuf` from source.
After executing the steps above, you will have successfully installed the grpc and protocol buffer libraries, including cpp plugin and the protoc compiler on your host environment. The above steps are described in detail in [Installing gRPC from source](https://github.com/grpc/grpc/blob/master/BUILDING.md) In the following, we cover two main aspects of porting gRPC to TizenRT, mainly details on how to build gRPC library, and how to develop, build and run applications that use gRPC.
