fix(doc): Fix an incorrect consensus-critical ZIP 212 comment #81

Job	Run time
Check if cached state disks exist for testnet / Check if cached state disks exist	59s
Check if cached state disks exist for Mainnet / Check if cached state disks exist	1m 2s
Build CI Docker / Build images	39s
Zebra tip	0s
Zebra tip on testnet	0s
Zebra checkpoint	0s
lightwalletd tip	0s
Generate checkpoints mainnet	0s
Zebra tip JSON-RPC	0s
Zebra tip update	0s
get block template	0s
submit block	0s
Generate checkpoints testnet	0s
Zebra checkpoint update	0s
lightwalletd tip update	0s
lightwalletd tip send	0s
lightwalletd GRPC tests	0s
Open or update issues for main branch failures	0s
	2m 40s

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