Update the loom rpc client to discard blockTime from logs

[enlight]

Loom chains have a non-standard blockTime field on the logs returned by eth_getLogs (and in receipts), this seems to trip up the indexer:

2019-10-31T05:37:01.552 application=indexer fetcher=block_catchup [error] Catchup index stream exited with reason ({:function_clause, [{EthereumJSONRPC.Log, :entry_to_elixir, [{"blockTime", "0x5dba72d6"}], [file: 'lib/ethereum_jsonrpc/log.ex', line: 170]}, {Map, :new_transform, 3, [file: 'lib/map.ex', line: 216]}, {Enum, :"-map/2-lists^map/1-0-", 2, [file: 'lib/enum.ex', line: 1336]}, {EthereumJSONRPC.Receipt, :entry_to_elixir, 1, [file: 'lib/ethereum_jsonrpc/receipt.ex', line: 272]}, {EthereumJSONRPC.Receipt, :entry_reducer, 2, [file: 'lib/ethereum_jsonrpc/receipt.ex', line: 218]}, {:maps, :fold_1, 3, [file: 'maps.erl', line: 232]}, {EthereumJSONRPC.Receipt, :to_elixir, 1, [file: 'lib/ethereum_jsonrpc/receipt.ex', line: 212]}, {Enum, :"-map/2-lists^map/1-0-", 2, [file: 'lib/enum.ex', line: 1336]}]}). Restarting

2019-10-31T05:37:01.554 [error] GenServer :block_catchup_sequencer terminating

 ** (FunctionClauseError) no function clause matching in EthereumJSONRPC.Log.entry_to_elixir/1

 (ethereum_jsonrpc) lib/ethereum_jsonrpc/log.ex:170: EthereumJSONRPC.Log.entry_to_elixir({"blockTime", "0x5dba72d6"})

 (elixir) lib/enum.ex:1336: Enum."-map/2-lists^map/1-0-"/2

 (ethereum_jsonrpc) lib/ethereum_jsonrpc/receipt.ex:212: EthereumJSONRPC.Receipt.to_elixir/1

I think the easiest way to fix this is to tweak the EthereumJSONRPC.Log.entry_to_elixir function to ignore the blockTime field. This should be a loom specific tweak, so maybe need to put this override in apps\ethereum_jsonrpc\lib\ethereum_jsonrpc\loom\logs.ex and then figure out how to get use it instead of the default implementation.