BUG: mislabeled dust tracer in non-ISOTHERMAL equation of state

[alexziab]

Describe the issue:

When assigning tracers to the dust fluid component, the label of the first tracer is "DustX_Vc-PRS" rather than "DustX_Vc-TR0" for all dust species X when not defining an ISOTHERMAL equation of state. Additional tracers are otherwise correctly labeled.

Error message:

runtime information:

On commit 9b2afc5, branch implicitDrag

[glesur]

fixed in #321