Parameter Bridge re-publishing vicon topics

[mhl787156]

It would appear that vicon publishing topics to /<vehicle_id>/mavros/vision_pose/pose gets republished by the parameter bridge.

Vicon publishes at 30hz

With the parameter bridge, we see that the publishing rate is 60hz

average rate: 61.681
	min: 0.003s max: 0.031s std dev: 0.01237s window: 10
average rate: 59.678
	min: 0.002s max: 0.034s std dev: 0.01447s window: 10
average rate: 60.210
	min: 0.002s max: 0.031s std dev: 0.01377s window: 10
average rate: 59.346
	min: 0.002s max: 0.036s std dev: 0.01439s window: 10
average rate: 57.816
	min: 0.002s max: 0.034s std dev: 0.01404s window: 10
average rate: 59.304
	min: 0.002s max: 0.036s std dev: 0.01185s window: 10
average rate: 59.755
	min: 0.002s max: 0.032s std dev: 0.01423s window: 10
average rate: 59.473
	min: 0.002s max: 0.032s std dev: 0.01397s window: 10
average rate: 61.668

If I restart the mavros container, during the period of the restart, we get an average rate of 30hz