Comment 7 for bug 1878923

Error in regiond.log is following:

2020-05-17 12:16:57 metadataserver.api: [critical] compute01.infra.lan(mq77wq): commissioning script '50-maas-01-commissioning' failed during post-processing.
 Traceback (most recent call last):
   File "/usr/lib/python3/dist-packages/metadataserver/api.py", line 802, in signal
     target_status = process(node, request, status)
   File "/usr/lib/python3/dist-packages/metadataserver/api.py", line 622, in _process_commissioning
     node, node.current_commissioning_script_set, request, status
   File "/usr/lib/python3/dist-packages/metadataserver/api.py", line 515, in _store_results
     **args, timedout=(status == SIGNAL_STATUS.TIMEDOUT)
   File "/usr/lib/python3/dist-packages/metadataserver/models/scriptresult.py", line 388, in store_result
     exit_status=self.exit_status,
 --- <exception caught here> ---
   File "/usr/lib/python3/dist-packages/metadataserver/api.py", line 441, in try_or_log_event
     func(*args, **kwargs)
   File "/usr/lib/python3/dist-packages/metadataserver/builtin_scripts/hooks.py", line 453, in process_lxd_results
     node.memory, numa_nodes = _parse_memory(data, numa_nodes)
   File "/usr/lib/python3/dist-packages/metadataserver/builtin_scripts/hooks.py", line 548, in _parse_memory
     memory_node["total"] / 1024 / 1024
 builtins.KeyError: 3