[FIX] b_w_shift: Issue with settings

There was an issue that shows an error message when trying to modify the
settings for shift in the website configuration.

This is due to a missing sequence in the database. I don't know why this
sequence where not present. But a simple query create it if it doesn't
exists.

beesdoo_website_shift/__openerp__.py

@@ -16,7 +16,7 @@
 
     'author': 'Rémy Taymans',
     'license': 'AGPL-3',
-    'version': '9.0.2.1',
+    'version': '9.0.2.1.1',
     'website': "https://github.com/beescoop/Obeesdoo",
 
     'category': 'Cooperative management',

beesdoo_website_shift/migrations/9.0.2.1.1/post-migrate.py

@@ -0,0 +1,11 @@
+# coding: utf-8
+
+
+def migrate(cr, version):
+    """Create a sequence for beesdoo_website_shift_config_settings."""
+    cr.execute(
+        """
+        CREATE SEQUENCE IF NOT EXISTS
+        beesdoo_website_shift_config_settings_id_seq
+        """
+    )