Bob,
The reason for the bypass resistor is that the indicator relay (most of them) are sensitive to the current flow.
What happens when a bulb blows? Fast flash. Why? Because the current drawn is lower than with a non-blown bulb.
LEDs draw low current, therefore with a standard relay you get a fast flash. So, to bring the current flow up to "normal" an additional resistor, wired in parallel to the LED, is required...
