Clarification regarding deprecated FDM message on next

On next we've disabled LaRCsim and UIUC FDMs, and those libraries are no longer in the codebase. The exception error suggests to rebuild FlightGear in order to enable those FDMs:

Is that actually possible though? I thought were totally removed, to the point where they can't be re-added at build time.

The SG_LOG console message is LaRCsim/UIUC support is removed from this version of FlightGear. Please use the 2024.1 release instead. which is probably a better solution for those who are absolutely committed to using them.

Assuming this is the case, I can go ahead and make an MR to change the message in that error pop-up to more closely match the SG_LOG statement. What do you think @zakalawe?