[FIX] base: reason json payload using get_data

Replace `httprequest.stream.read()` by `httprequest.get_data()` so the
payload content remains available: get_data stores the request body (by
default) so it remains available for alternative processing or checks
(MAC checks for webhook validations for instance). With `stream.read()`,
once the data is read if it's not stored separately it is lost.

doc/cla/individual/kirca.md

@@ -9,3 +9,4 @@ declaration.
 Signed,
 
 Kiril Vangelovski kiril@hacbee.com https://github.com/kirca
+Kiril Vangelovski kiril@lambda-is.com https://github.com/kirca

odoo/http.py

@@ -603,7 +603,7 @@ class JsonRequest(WebRequest):
             request = self.session.pop('jsonp_request_%s' % (request_id,), '{}')
         else:
             # regular jsonrpc2
-            request = self.httprequest.stream.read().decode(self.httprequest.charset)
+            request = self.httprequest.get_data().decode(self.httprequest.charset)
 
         # Read POST content or POST Form Data named "request"
         try: