Proxy: Fix unready forwarded requests causing crash

See merge request nexedi/slapos.core!490

slapos/proxy/views.py

@@ -714,6 +714,11 @@ def forwardRequestToExternalMaster(master_url, request_form):
   partition._master_url = master_url # type: ignore
   partition._connection_helper = None
   partition._software_release_document = request_form['software_release'] # type: ignore
+
+  if partition._request_dict is not None:
+    # ResourceNotReady
+    abort(408)
+
   return dumps(partition)
 
 def getAllocatedInstance(partition_reference):

slapos/slap/slap.py

@@ -469,7 +469,7 @@ class ComputerPartition(SlapRequester):
     self._updateTransactionFile(partition_reference=None)
 
   def __getinitargs__(self):
-    return (self._computer_id, self._partition_id, )
+    return (self._computer_id, self._partition_id, self._request_dict)
 
   def _updateTransactionFile(self, partition_reference=None):
     """