Adds user filter for DeviceToken

tournaments/admin.py

@@ -111,6 +111,7 @@ class LogAdmin(admin.ModelAdmin):
 
 class DeviceTokenAdmin(admin.ModelAdmin):
     list_display = ['user', 'value']
+    list_filter = ['user']
 
 class DrawLogAdmin(admin.ModelAdmin):
     list_display = ['tournament', 'draw_date', 'draw_seed', 'draw_match_index', 'draw_team_position']