[FIX] website_livechat: set correct website_visitor col type

The `create_column` in auto_init was set to "BOOLEAN" instead of
"int4". This is a relational field, so "BOOLEAN" prevent setting
any operator other than with id 0 or 1.

closes odoo/odoo#108563

Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/website_livechat/models/website_visitor.py

@@ -23,7 +23,7 @@ class WebsiteVisitor(models.Model):
         # Skip the computation of the field `livechat_operator_id` at the module installation
         # We can assume no livechat operator attributed to visitor if it was not installed
         if not column_exists(self.env.cr, "website_visitor", "livechat_operator_id"):
-            create_column(self.env.cr, "website_visitor", "livechat_operator_id", "BOOLEAN")
+            create_column(self.env.cr, "website_visitor", "livechat_operator_id", "int4")
 
         return super()._auto_init()