Impacted versions: 8-11

## Current behavior:

If during an XMLRPC call you try to get anything from `http.request`, you'd get a `RuntimeError` such as this one:

```
Traceback (most recent call last):
  File "/opt/odoo/custom/src/odoo/odoo/service/wsgi_server.py", line 56, in xmlrpc_return
    result = odoo.http.dispatch_rpc(service, method, params)
  File "/opt/odoo/custom/src/odoo/odoo/http.py", line 118, in dispatch_rpc
    result = dispatch(method, params)
  File "/opt/odoo/custom/src/odoo/odoo/service/common.py", line 57, in dispatch
    return g[exp_method_name](*params)
  [...]
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 343, in __getattr__
    return getattr(self._get_current_object(), name)
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 302, in _get_current_object
    return self.__local()
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 135, in _lookup
    raise RuntimeError(\'object unbound\')
RuntimeError: object unbound
```

This renders imposible in practice to fix issues such as https://github.com/OCA/server-tools/issues/1125 or to implement https://github.com/odoo/odoo/pull/22212#issuecomment-380425764.

## Expected behavior:

XML-RPC calls should have request, since after all they belong to one. Otherwise, at least there should be an alternate way to access the request parameters.

Fix for v12: https://github.com/odoo/odoo/pull/24187

@Tecnativa
odoo/http.py
"""Root WSGI application for the OpenERP Web Client.
    """
    def __init__(self):
        self._loaded = False
    @lazy_property
    def session_store(self):
        
        path = odoo.tools.config.session_dir
        _logger.debug('HTTP sessions stored in: %s', path)
        return werkzeug.contrib.sessions.FilesystemSessionStore(path, session_class=OpenERPSession)
    @lazy_property
    def nodb_routing_map(self):
        _logger.info("Generating nondb routing")
        return routing_map([''] + odoo.conf.server_wide_modules, True)
    def __call__(self, environ, start_response):
        """ Handle a WSGI request
        """
        if not self._loaded:
            self._loaded = True
            self.load_addons()
        return self.dispatch(environ, start_response)
    def load_addons(self):