Add server side invalid document template

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

mayan/apps/documents/apps.py

@@ -14,7 +14,7 @@ from mayan.apps.common import (
     MayanAppConfig, MissingItem, menu_facet, menu_main, menu_object,
     menu_secondary, menu_setup, menu_sidebar, menu_multi_item, menu_tools
 )
-from mayan.apps.common.classes import ModelField
+from mayan.apps.common.classes import ModelField, Template
 from mayan.apps.common.signals import post_initial_setup
 from mayan.apps.common.widgets import TwoStateWidget
 from mayan.apps.dashboards.dashboards import dashboard_main
@@ -333,6 +333,11 @@ class DocumentsApp(MayanAppConfig):
             func=lambda context: context['object'].documents.count()
         )
 
+        Template(
+            name='invalid_document',
+            template_name='documents/invalid_document.html'
+        )
+
         app.conf.CELERYBEAT_SCHEDULE.update(
             {
                 'task_check_delete_periods': {