Use fallback value for charset, url_charset and encoding_errors

Werkzeug 3.0 removes those attributes.

Closes #12604
(grafted from 0f5c7ceb4ea70a844ee660a678cc0b2b4643167e)

--HG--
branch : 6.0

trytond/trytond/protocols/jsonrpc.py

@@ -126,7 +126,8 @@ class JSONRequest(Request):
             try:
                 return json.loads(
                     self.decoded_data.decode(
-                        self.charset, self.encoding_errors),
+                        getattr(self, 'charset', 'utf-8'),
+                        getattr(self, 'encoding_errors', 'replace')),
                     object_hook=JSONDecoder())
             except Exception:
                 raise BadRequest('Unable to read JSON request')

trytond/trytond/protocols/wrappers.py

@@ -35,7 +35,7 @@ class Request(_Request):
             if self.url is None or isinstance(self.url, str):
                 url = self.url
             else:
-                url = self.url.decode(self.url_charset)
+                url = self.url.decode(getattr(self, 'url_charset', 'utf-8'))
             auth = self.authorization
             if auth:
                 args.append("%s@%s" % (