fix realtime fetcher small skips feature

If indexing is started from scratch, realtime fetcher
tries to index large ranges of blocks. For example, 5..1852044.
It produces errors like
`failed to fetch: :emfile.  Block will be retried by catchup indexer`

This PR limits the number of blocks to 10

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/transaction.ex

@@ -308,7 +308,7 @@ defmodule EthereumJSONRPC.Transaction do
   end
 
   def to_elixir(transaction) when is_binary(transaction) do
-    Logger.warn(["Fetched transaction is not full: ", transaction])
+    #    Logger.warn(["Fetched transaction is not full: ", transaction])
 
     nil
   end

apps/indexer/lib/indexer/block/realtime/fetcher.ex

@@ -250,7 +250,11 @@ defmodule Indexer.Block.Realtime.Fetcher do
         [number]
 
       true ->
-        (previous_number + 1)..number
+        if number - previous_number - 1 > 10 do
+          (number - 10)..number
+        else
+          (previous_number + 1)..number
+        end
     end
   end