Cannot load pages due to old Pylons route syntax

[frafra]

Related to: ckan/ckan#6263

ERROR [ckan.config.middleware.flask_app] not enough values to unpack (expected 2, got 1)
Traceback (most recent call last):
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/flask/app.py", line 1516, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/flask/app.py", line 1502, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)
  File "/usr/lib/ckan/venv/src/ckan/ckan/config/middleware/../../views/dataset.py", line 507, in read
    return base.render(
  File "/usr/lib/ckan/venv/src/ckan/ckan/lib/base.py", line 101, in render
    return flask_render_template(template_name, **extra_vars)
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/flask/templating.py", line 147, in render_template
    return _render(
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/flask/templating.py", line 128, in _render
    rv = template.render(context)
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/jinja2/environment.py", line 1304, in render
    self.environment.handle_exception()
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/jinja2/environment.py", line 925, in handle_exception
    raise rewrite_traceback_stack(source=source)
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/ckanext/harvest/plugin/../templates/source/read.html", line 1, in top-level template code
    {% extends "source/read_base.html" %}
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/ckanext/harvest/plugin/../templates/source/read_base.html", line 1, in top-level template code
    {% extends "source/base.html" %}
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/ckanext/harvest/plugin/../templates/source/base.html", line 6, in top-level template code
    {% set authorized_user = h.check_access('harvest_source_create') %}
  File "/usr/lib/ckan/venv/src/ckan/ckan/templates/page.html", line 1, in top-level template code
    {% extends "base.html" %}
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/ckanext/harvest/plugin/../templates/base.html", line 1, in top-level template code
    {% ckan_extends %}
  File "/usr/lib/ckan/venv/src/ckan/ckan/templates/base.html", line 106, in top-level template code
    {%- block page %}{% endblock -%}
  File "/usr/lib/ckan/venv/src/ckan/ckan/templates/page.html", line 19, in block 'page'
    {%- block content %}
  File "/usr/lib/ckan/venv/src/ckan/ckan/templates/page.html", line 22, in block 'content'
    {% block main_content %}
  File "/usr/lib/ckan/venv/src/ckan/ckan/templates/page.html", line 74, in block 'main_content'
    {% block primary %}
  File "/usr/lib/ckan/venv/src/ckan/ckan/templates/page.html", line 87, in block 'primary'
    {% block primary_content %}
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/ckanext/harvest/plugin/../templates/source/read_base.html", line 41, in block 'primary_content'
    {% block page_header %}
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/ckanext/harvest/plugin/../templates/source/read_base.html", line 49, in block 'page_header'
    {% block page_header_tabs %}
  File "/usr/lib/ckan/venv/lib/python3.8/site-packages/ckanext/harvest/plugin/../templates/source/read_base.html", line 50, in block 'page_header_tabs'
    {{ h.build_nav_icon('{0}_read'.format(c.dataset_type), _('Datasets'), id=harvest_source.name, icon='sitemap') }}
  File "/usr/lib/ckan/venv/src/ckan/ckan/lib/helpers.py", line 963, in build_nav_icon
    return _make_menu_item(menu_item, title, **kw)
  File "/usr/lib/ckan/venv/src/ckan/ckan/lib/helpers.py", line 1038, in _make_menu_item
    controller, action = menu_item.split('.')
ValueError: not enough values to unpack (expected 2, got 1)