Remove unneeded code

app/assets/javascripts/copy_as_gfm.js.es6

@@ -249,8 +249,8 @@
 
   class CopyAsGFM {
     constructor() {
-      $(document).on('copy', '.md, .wiki', this.handleCopy.bind(this));
-      $(document).on('paste', '.js-gfm-input', this.handlePaste.bind(this));
+      $(document).on('copy', '.md, .wiki', this.handleCopy);
+      $(document).on('paste', '.js-gfm-input', this.handlePaste);
     }
 
     handleCopy(e) {

app/assets/javascripts/lib/utils/common_utils.js.es6

@@ -161,8 +161,6 @@
     };
 
     w.gl.utils.getSelectedFragment = () => {
-      if (!window.getSelection) return null;
-
       const selection = window.getSelection();
       if (!selection.rangeCount || selection.rangeCount === 0) return null;