These properties were deleted in r4386 but this causes fgfs 2019.1.1
to crash on startup with the message:
FGPropertyManager::GetNode() No node found for fcs/throttle-pos-norm
In file /home/lbrenta/.fgfs/Aircraft/an24b/Engines/ai24.xml: line 49
Thread 1 "fgfs" received signal SIGSEGV, Segmentation fault.
There may be a better fix for this bug.
