use "C-j" & "C-k" in ivy

lisp/completion.el

@@ -85,12 +85,11 @@
 
   (global-set-key "\C-s" 'swiper)
 
-  ;; (dolist (map (list ivy-minibuffer-map
-  ;;                    ivy-switch-buffer-map
-  ;;                    ivy-reverse-i-search-map))
-  ;;   (define-key map (kbd "C-j") 'ivy-next-line)
-  ;;   (define-key map (kbd "C-k") 'ivy-previous-line))
-
+  (dolist (map (list ivy-minibuffer-map
+                     ivy-switch-buffer-map
+                     ivy-reverse-i-search-map))
+    (define-key map (kbd "C-j") 'ivy-next-line)
+    (define-key map (kbd "C-k") 'ivy-previous-line))
 
   :bind
   (("C-c s s" . 'swiper)