docs(readme): fix icon url

Author: joshwiens

README.md

@@ -6,8 +6,6 @@
 [![chat][chat]][chat-url]
 
 <div align="center">
-  <img width="200" height="200"
-    src="https://cdn.rawgit.com/webpack/file-loader/tree/master/.github/assets/file_loader_icon.svg">
   <a href="https://github.com/webpack/webpack">
     <img width="200" height="200"
       src="https://webpack.js.org/assets/icon-square-big.svg">