Installing for subsequent repositories silently fails after first repo install

Hi again,

We use two repositories, and when we try to install for both of them it silently fails on the second one. I think this can be solved by adding the telemetry_prefix to the handler_id in the call to :telemetry.attach/4.

  @doc """
  Attaches `telemetry_handler/4` to application.
  """
  @spec install(repo_module :: module()) :: :ok
  def install(repo_module) when is_atom(repo_module) do
    config = repo_module.config()

    if config[:log] == false do
      :telemetry.attach(
        ["ecto.dev_logger"] ++ config[:telemetry_prefix],
        config[:telemetry_prefix] ++ [:query],
        &__MODULE__.telemetry_handler/4,
        nil
      )
    else
      :ok
    end
  end

I also changed the if statement so that any response from the call to :telemetry.attach/4 doesn't get swallowed.

Happy to submit this as a PR if you agree that this makes sense? Also happy for anyone else to do this or solve in any other way :-)

fuelen / ecto_dev_logger

Installing for subsequent repositories silently fails after first repo install #10