Fix show error when pool address is null
Fix show error when pool address is null

Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano