HeatEnergySource::emissions_per_minute wrong "default"

[BrainGamer_]

HeatEnergySource::emissions_per_minute is overridden since heat energy sources don't support pollution. It mentions a default value of 0 but the type of emissions in 2.0 is dictionary[AirbornePollutantID -> double] and not just double anymore.

I think not specifying a default value and maybe extending the overridden description a bit would be more correct in this case.

[Therenas]

Thanks, I removed the default value for the next release.