posix rcS: remove various SITL custom settings
posix rcS: remove various SITL custom settings

because we need to have SITL simulation as realistic as possible
compared to a real flight with default settings such that we
either fix the problems or adjust the defaults already in SITL testing.

acfloria/Firmware,PX4/Firmware,acfloria/Firmware,krbeverx/Firmware,PX4/Firmware,acfloria/Firmware,PX4/Firmware,PX4/Firmware,krbeverx/Firmware,krbeverx/Firmware,acfloria/Firmware,krbeverx/Firmware,krbeverx/Firmware,acfloria/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,PX4/Firmware,krbeverx/Firmware,acfloria/Firmware,acfloria/Firmware