add option to disable block rewards in indexer config

[nervehammer]

Not all chains distribute block reward, e.g. SpringChain. If chain don't have block reward, console is spammed with error: application=indexer fetcher=block_reward count=10 error_count=10 [error] failed to fetch: @㍪: (404) Not Found

Fixes #1526 and #1563.

Just uncomment the line config :indexer, Indexer.Block.Reward.Supervisor, disabled?: true in apps/indexer/config/config.exs

[nervehammer]

nervehammer@MonsterPad:~/push/blockscout$ mix test --exclude no_geth
==> ethereum_jsonrpc
Excluding tags: [:no_geth]

..........................warning: deprecated time unit: :seconds. A time unit should be :second, :millisecond, :microsecond, :nanosecond, or a positive integer
  (elixir) lib/calendar/iso.ex:703: Calendar.ISO.from_unix/2
  (elixir) lib/calendar/datetime.ex:118: DateTime.from_unix/3
  (elixir) lib/calendar/datetime.ex:166: DateTime.from_unix!/3
  (ethereum_jsonrpc) lib/ethereum_jsonrpc/block.ex:447: EthereumJSONRPC.Block.entry_to_elixir/1
  (elixir) lib/map.ex:210: Map.new_transform/3
  (elixir) lib/enum.ex:1327: Enum."-map/2-lists^map/1-0-"/2
  (for doctest at) lib/ethereum_jsonrpc/blocks.ex:276: EthereumJSONRPC.BlocksTest."doctest EthereumJSONRPC.Blocks.to_elixir/1 (4)"/1
  (ex_unit) lib/ex_unit/runner.ex:355: ExUnit.Runner.exec_test/1
  (stdlib) timer.erl:166: :timer.tc/1
  (ex_unit) lib/ex_unit/runner.ex:306: anonymous fn/4 in ExUnit.Runner.spawn_test_monitor/4

warning: deprecated time unit: :seconds. A time unit should be :second, :millisecond, :microsecond, :nanosecond, or a positive integer
  (elixir) lib/calendar/iso.ex:717: Calendar.ISO.precision_for_unit/1
  (elixir) lib/calendar/iso.ex:708: Calendar.ISO.from_unix/2
  (elixir) lib/calendar/datetime.ex:118: DateTime.from_unix/3
  (elixir) lib/calendar/datetime.ex:166: DateTime.from_unix!/3
  (ethereum_jsonrpc) lib/ethereum_jsonrpc/block.ex:447: EthereumJSONRPC.Block.entry_to_elixir/1
  (elixir) lib/map.ex:210: Map.new_transform/3
  (for doctest at) lib/ethereum_jsonrpc/block.ex:372: EthereumJSONRPC.BlockTest."doctest EthereumJSONRPC.Block.to_elixir/1 (5)"/1
  (ex_unit) lib/ex_unit/runner.ex:355: ExUnit.Runner.exec_test/1
  (stdlib) timer.erl:166: :timer.tc/1
  (ex_unit) lib/ex_unit/runner.ex:306: anonymous fn/4 in ExUnit.Runner.spawn_test_monitor/4

.............................................................................................

Finished in 0.9 seconds
50 doctests, 86 tests, 0 failures, 17 excluded

ran same test locally everything is fine @vbaranov , @zachdaniel

[smartblockdev]

application=indexer fetcher=block_reward count=10 error_count=10 [error] failed to fetch: @g: (404) Not Found
@f: (404) Not Found
@e: (404) Not Found
@d: (404) Not Found
@C: (404) Not Found
@b: (404) Not Found
@A: (404) Not Found
@@: (404) Not Found
@?: (404) Not Found
@: (404) Not Found

i am facing this issue please help,i also uncomment the "uncomment the line config :indexer, Indexer.Block.Reward.Supervisor, disabled?: true" in apps/indexer/config/config.exs but no luck.