Moved the turbolinks listener from application.js to the corresponding issuable sidebar file

app/assets/javascripts/application.js

@@ -248,14 +248,6 @@
     $window.off('resize.app').on('resize.app', function () {
       return fitSidebarForSize();
     });
-    window.addEventListener('beforeunload', function() {
-      // collapsed_gutter cookie hides the sidebar
-      var bpBreakpoint = bp.getBreakpointSize();
-      if (bpBreakpoint === 'xs' || bpBreakpoint === 'sm') {
-        Cookies.set('collapsed_gutter', true);
-      }
-    });
-
     gl.awardsHandler = new AwardsHandler();
     new Aside();
     // bind sidebar events

app/assets/javascripts/issuable_context.js

 /* eslint-disable func-names, space-before-function-paren, wrap-iife, no-new, comma-dangle, quotes, prefer-arrow-callback, consistent-return, one-var, no-var, one-var-declaration-per-line, no-underscore-dangle, max-len */
 /* global UsersSelect */
+/* global Cookies */
+/* global bp */
 
 (function() {
   this.IssuableContext = (function() {
@@ -37,6 +39,13 @@
           }, 0);
         }
       });
+      window.addEventListener('beforeunload', function() {
+        // collapsed_gutter cookie hides the sidebar
+        var bpBreakpoint = bp.getBreakpointSize();
+        if (bpBreakpoint === 'xs' || bpBreakpoint === 'sm') {
+          Cookies.set('collapsed_gutter', true);
+        }
+      });
       $(".right-sidebar").niceScroll();
     }