fix chainid error

[araskachoi]

Closes: #XXX

Description

There was an issue where the ethermintd start cmd requires a chainID within its context. However, there was none passed. This PR will allow for the clientCtx.ChainID to be passed as a flag (ethermintd start --chain-id $CHAINID) or the chainID will be read from a valid geneisfile from serverCtx.Config.GenesisFile().

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[araskachoi]

This resolves the invalid Chain ID error that was throwing from ethermintd start.

However, there is another issue that is not resolved here. The error log is as below:

E[2021-01-29|01:39:24.555] failed to get keybase info                   module=json-rpc namespace=eth error="unknown keyring backend "
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x110 pc=0x1989510]

goroutine 184 [running]:
github.com/cosmos/ethermint/rpc/namespaces/eth/filters.(*EventSystem).subscribe(0xc000c14580, 0xc0001dc000, 0xc000081560, 0x471e65, 0xc000529800, 0x200000003)
        /ethermint/rpc/namespaces/eth/filters/filter_system.go:114 +0x410
github.com/cosmos/ethermint/rpc/namespaces/eth/filters.EventSystem.SubscribePendingTxs(0x2298c40, 0xc000042080, 0x0, 0x0, 0x0, 0xc00056c420, 0x0, 0x0, 0x0, 0x0, ...)
        /ethermint/rpc/namespaces/eth/filters/filter_system.go:249 +0x22f
github.com/cosmos/ethermint/rpc/namespaces/eth/filters.(*EventSystem).eventLoop(0xc000d00680)
        /ethermint/rpc/namespaces/eth/filters/filter_system.go:295 +0x98
created by github.com/cosmos/ethermint/rpc/namespaces/eth/filters.NewEventSystem
        /ethermint/rpc/namespaces/eth/filters/filter_system.go:88 +0x24d

[WIP] - Will continue to investigate and resolve.

[fedekunze]

this is now fixed on development