[FIX] mail: fix get_sys_logs to have the same behaviour than previous…

… version

After convertion python2 to python3, the arg0 was send as dict instead
of one string. We prefer to keep the same behaviour that previously.

addons/mail/models/update.py

@@ -13,8 +13,7 @@
 from odoo.exceptions import UserError
 from odoo.models import AbstractModel
 from odoo.tools.translate import _
-from odoo.tools import config
-from odoo.tools import misc
+from odoo.tools import config, misc, ustr
 
 _logger = logging.getLogger(__name__)
 
@@ -71,7 +70,7 @@ def _get_sys_logs(self):
         Utility method to send a publisher warranty get logs messages.
         """
         msg = self._get_message()
-        arguments = {'arg0': msg, "action": "update"}
+        arguments = {'arg0': ustr(msg), "action": "update"}
 
         url = config.get("publisher_warranty_url")