fix alternancy load statistics

Signed-off-by: Alexandre Arias <apa13@inf.ufpr.br>

app/controllers/management/statistics_controller.rb

 class Management::StatisticsController < ManagementController
   include RepositoriesProxy
   #before_action :set_statistics
+  before_action :authenticate_user!, except: [:index, :show, :like]
 
-  @@flag = 0
+  @@flag = 0  
 
   def index
-    if @@flag == 0
+    if @@flag == 0 || @@user != current_user
+      @@user =  current_user
       set_statistics
       @@flag = 1
     end
@@ -32,8 +34,8 @@ class Management::StatisticsController < ManagementController
 
 
   def learning_objects
-    if @@flag == 0
-      set_statistics
+    if @@flag == 0 || @@user != current_user
+      @@user =  current_user
       @@flag = 1
     end
     @n_learning_objects = @@n_learning_objects