Code Effeciency Project:  Vent scrubbers have a bit more sanity.

No longer checking for 0.00000000000000000000000001 moles of toxins scrubers can only detect stuff worse then 0.001 moles.

Have a nice day.
Merge pull request #4691 from Ccomp5950/ventfix

Code Effeciency Project:  Vent scrubbers have a bit more sanity.