that blockchain_height key returned from getinfo:
"auto_connect": true,
"blockchain_height": 878674,
"connected": true,
"default_wallet": "/home/geremia/.electrum/wallets/default_wallet",
"fee_per_kb": 2457,
"network": "mainnet",
"path": "/home/geremia/.electrum",
"server": "udfpzbte2hommnvag5f3qlouqkhvp3xybhlus2yvfeqdwlhjroe4bbyd.onion",
"server_height": 878674,
"spv_nodes": 10,
"version": "4.5.8"