Remove 2nd CopyWebpackPlugin var

Found using sonar scanner.

Change-Id: I7ca70f2d13a8adfeebfee2b727ffed7c118a89bc
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/webpack.config.js b/webpack.config.js
index 6b3e899..d4130f6 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -8,7 +8,6 @@
 var CopyWebpackPlugin = require('copy-webpack-plugin');
 var CompressionPlugin = require('compression-webpack-plugin');
 var AssetsPlugin = require('assets-webpack-plugin');
-var CopyWebpackPlugin = require('copy-webpack-plugin');
 var path = require('path');
 var UglifyJsPlugin = require('uglifyjs-webpack-plugin');