File "electrum/gui/qt/network_dialog.py", line 64, in on_update
  File "electrum/gui/qt/network_dialog.py", line 376, in update
  File "electrum/blockchain.py", line 206, in get_name
  File "electrum/blockchain.py", line 449, in get_hash
  File "electrum/blockchain.py", line 182, in func_wrapper
  File "electrum/blockchain.py", line 424, in read_header