Made thread and images list read-only in admin (BB-55)

boards/admin.py

@@ -10,7 +10,7 b' class PostAdmin(admin.ModelAdmin):'
     list_filter = ('pub_time',)
     search_fields = ('id', 'title', 'text')
     exclude = ('referenced_posts', 'refmap')
-    readonly_fields = ('poster_ip', 'threads')
+    readonly_fields = ('poster_ip', 'threads', 'thread', 'images')
 
     def ban_poster(self, request, queryset):
         bans = 0