Prevent to get user_id from request without view_args

If user_id is accessed before view_args has been setup, we should not cache
`None` as value but instead raise an exception.
The `user_id` may be accessed before the mapping if the request is logged
because the representation of the request used the `rpc_method` which needs to
parse the request data. But since 1923117e935d parsing compressed content is
only allowed for request with `user_id`.
So we can no more include the `rpc_method` is the request has not yet been
mapped and so it has a `view_args`.

Closes #13203
(grafted from 0630029c1d5a0a2c7bd45086957f2e0fbed4c427)

--HG--
branch : 7.0

trytond/trytond/protocols/wrappers.py

@@ -62,7 +62,8 @@ class Request(_Request):
                 args.append(self.remote_addr)
             args.append("'%s'" % url)
             args.append("[%s]" % self.method)
-            args.append("%s" % (self.rpc_method or ''))
+            if self.view_args:
+                args.append("%s" % (self.rpc_method or ''))
         except Exception:
             args.append("(invalid WSGI environ)")
         return "<%s %s>" % (
@@ -109,8 +110,7 @@ class Request(_Request):
 
     @cached_property
     def user_id(self):
-        if not self.view_args:
-            return None
+        assert self.view_args is not None
         database_name = self.view_args.get('database_name')
         if not database_name:
             return None