fix test

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/rolling_window.ex

@@ -211,6 +211,9 @@ defmodule EthereumJSONRPC.RollingWindow do
   """
   @spec inspect(table :: atom, key :: term()) :: nonempty_list(non_neg_integer)
   def inspect(table, key) do
+    if :ets.whereis(table) == :undefined do
+      []
+    else
       case :ets.lookup(table, key) do
         [{_, current_window, windows}] ->
           [current_window | windows]
@@ -220,3 +223,4 @@ defmodule EthereumJSONRPC.RollingWindow do
       end
     end
   end
+end