delete all duplicate empty blanks (#5758)

Signed-off-by: Xiang Dai <764524258@qq.com>
diff --git a/js/README.md b/js/README.md
index 2c14222..3635028 100644
--- a/js/README.md
+++ b/js/README.md
@@ -19,8 +19,8 @@
 To use Protocol Buffers with JavaScript, you need two main components:
 
 1. The protobuf runtime library.  You can install this with
-   `npm install google-protobuf`, or use the files in this directory.  
-    If npm is not being used, as of 3.3.0, the files needed are located in binary subdirectory; 
+   `npm install google-protobuf`, or use the files in this directory.
+    If npm is not being used, as of 3.3.0, the files needed are located in binary subdirectory;
     arith.js, constants.js, decoder.js, encoder.js, map.js, message.js, reader.js, utils.js, writer.js
 2. The Protocol Compiler `protoc`.  This translates `.proto` files
    into `.js` files.  The compiler is not currently available via