Light rain causes intermittent DRS enablement

[WilliamGawlik]

No description provided.

[tomasastary]

In function:
function weatherTreeNode(sim, rc)
math.floor(sim.rainIntensity / 0.003) //at about 0.33% of rain intensity floor flapping between 0 and 1 (max clamp).

therefore totalWetness jumps down to zero value when multiplied by zero):
local totalWetness = ((sim.rainWetness * 10000 * 3.75) + (sim.rainWater * 100 * 12.5)) * (isRaining and 1 or 0)

so DRS is flapping when rainIntensity is flapping up and down around 0.33%