Raise last retry exception from JSON-RPC request

Closes #15008
(grafted from 3e2a195d2b333fda531f719c4b6c69a7c5f2e1c0)

--HG--
branch : 8.0

tryton/tryton/jsonrpc.py

@@ -294,7 +294,8 @@ class ServerProxy(xmlrpc.client.ServerProxy):
 
         try:
             try:
-                for i in range(5):
+                count, retry = 0, 5
+                while True:
                     try:
                         response = self.__transport.request(
                             self.__host,
@@ -304,17 +305,21 @@ class ServerProxy(xmlrpc.client.ServerProxy):
                             )
                         break
                     except xmlrpc.client.ProtocolError as e:
-                        if e.errcode == HTTPStatus.SERVICE_UNAVAILABLE:
+                        if (e.errcode == HTTPStatus.SERVICE_UNAVAILABLE
+                                and count < retry):
+                            count += 1
                             try:
-                                delay = int(e.headers.get('Retry-After', i))
+                                delay = int(
+                                    e.headers.get('Retry-After', count))
                             except ValueError:
                                 if isinstance(
                                         e.errcode, HTTPStatus.GATEWAY_TIMEOUT):
                                     # Do not retry on timeout without delay
                                     raise
-                                delay = i
+                                delay = count
                             delay = min(delay, 10)
                             time.sleep(delay)
+                            continue
                         else:
                             raise
             except (socket.error, http.client.HTTPException) as v: