Update exception detection to work with Python3 format.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/document_states/classes.py

@@ -66,7 +66,7 @@ class WorkflowAction(six.with_metaclass(WorkflowActionMetaclass, WorkflowActionB
             try:
                 import_module('{}.workflow_actions'.format(app.name))
             except ImportError as exception:
-                if force_text(exception) != 'No module named workflow_actions':
+                if force_text(exception) not in ('No module named workflow_actions', 'No module named \'{}.workflow_actions\''.format(app.name)):
                     logger.error(
                         'Error importing %s workflow_actions.py file; %s',
                         app.name, exception