[py3] Use desktop lib smart_unicode to not crash admin page
ImportError: cannot import name 'smart_unicode'
<%!
from django.urls import reverse
-from django.utils.encoding import smart_unicode
from django.utils.translation import ugettext as _
from metadata.conf import OPTIMIZER, has_optimizer
from desktop.auth.backend import is_admin
+from desktop.lib.i18n import smart_unicode
from desktop.conf import has_connectors
from desktop.views import commonheader, commonfooter
%>
